--- product_id: 378663409 title: "Replacement Back Battery Door Adhesive for Samsung Galaxy S21 Ultra 5G SM-G998U G998U1 G998 - Pre-Cut Double Sided Glue Tape Sticker - 2 Pack" brand: "phonsun" price: "€ 15.39" currency: EUR in_stock: true reviews_count: 11 category: "Phonsun" url: https://www.desertcart.gr/products/378663409-replacement-back-battery-door-adhesive-for-samsung-galaxy-s21-ultra store_origin: GR region: Greece --- # Precision pre-cut fit DIY-friendly easy install 3-layer shock-absorbing seal Replacement Back Battery Door Adhesive for Samsung Galaxy S21 Ultra 5G SM-G998U G998U1 G998 - Pre-Cut Double Sided Glue Tape Sticker - 2 Pack **Brand:** phonsun **Price:** € 15.39 **Availability:** ✅ In Stock ## Summary > 🔧 Seal it like a pro, protect like a boss! ## Quick Answers - **What is this?** Replacement Back Battery Door Adhesive for Samsung Galaxy S21 Ultra 5G SM-G998U G998U1 G998 - Pre-Cut Double Sided Glue Tape Sticker - 2 Pack by phonsun - **How much does it cost?** € 15.39 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/378663409-replacement-back-battery-door-adhesive-for-samsung-galaxy-s21-ultra) ## Best For - phonsun enthusiasts ## Why This Product - Trusted phonsun brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Double Pack Backup:** Two adhesive sets included—because one flawless repair deserves a risk-free spare. - • **Dust & Impact Barrier:** Black PE foam core seals out dust and cushions your back glass against everyday bumps. - • **Flawless Fit Every Time:** Machine-cut to perfectly match your Galaxy S21 Ultra frame—no trimming, no guesswork. - • **DIY Repair Made Effortless:** Pre-cut design and clear instructions let you restore your phone like a pro, no messy glue required. - • **Triple-Layer Tech for Ultimate Protection:** High-tack adhesive, shock-absorbing foam, and glass-bonding layer combine for factory-grade durability. ## Overview This PHONSUN Replacement Back Battery Door Adhesive is a precision-engineered, triple-layer pre-cut tape designed exclusively for the Samsung Galaxy S21 Ultra 5G. Featuring a high-tack metal frame adhesive, shock-absorbing foam core, and glass-bonding layer, it ensures a perfect, durable seal that protects against dust and impact. The 2-pack bundle offers a risk-free DIY repair experience with easy installation and factory-level fit. ## Description Professional Repair Grade: 3-Layer Composite Adhesive for S21 Ultra Restore your phone’s integrity with our industrial-strength back cover adhesive. Unlike standard single-layer stickers, our product is engineered with a triple-layer "sandwich" structure designed specifically for the rigors of mobile repair. Why Choose Our 3-Layer Structure? White High-Tack Layer: Formulated to grip the micro-textures of the metal frame for maximum adhesion. Black PE Foam Core: Provides essential shock absorption to protect the rear glass and acts as a closed-cell barrier against dust and moisture. Black Glass-Bonding Layer: Optimized for a smooth, flush finish with the glass back panel, ensuring a clean, factory-like appearance. Precision Pre-Cut for Hassle-Free DIY Skip the frustration of manual trimming. Each sticker is precisely machine-cut to match the internal contours of the Samsung Galaxy S21 Ultra (SM-G998U/G998U1/G998). This ensures: Zero Overhang: No messy glue leaking from the edges. Perfect Alignment: Holes for cameras and sensors are accurately positioned. Beginner Friendly: Makes the repair process faster and significantly reduces the risk of error. The Truth About Water Resistance We believe in being honest with our customers: While our adhesive material is designed for sealing, achieving a waterproof result depends 100% on the quality of installation. To get the best possible seal, you must: Thoroughly Clean: Remove every bit of old adhesive residue using 90%+ isopropyl alcohol. Ensure Flush Fit: Verify the frame is not bent and the back glass sits perfectly flat. Apply Pressure: After sticking, apply firm, even pressure for at least 30 seconds to fully activate the bond. What’s in the Box? 2 x Pre-Cut Back Battery Door Adhesives (A spare is included for your peace of mind). Review: Perfect fir and adherence - M6 samsung s21 ultra overheated while playing a game. This caused the sealant to fail resulting in a loose backglass. After cleaning the residual off, this installed easily. I compressed the phone over night and found it perfectly adhered. I highly recommend it. Review: Excelente producto - Excelente producto ## Features - Perfect Fit with Precision Pre-Cutting. Specifically machine-cut to the exact dimensions of the Samsung Galaxy S21 Ultra 5G (SM-G998U/G998U1/G998). This adhesive eliminates the need for manual trimming, ensuring a 100% accurate fit that matches the original phone frame contours perfectly. - Professional 3-Layer Structure. Our professional-grade glue features a Triple-Layer Composite: A white high-tack layer for the metal frame, a black shock-absorbing foam core, and a black adhesive layer for the glass. This "sandwich" design provides superior bonding and cushioning compared to thin, single-layer stickers. - Easy DIY Installation. The Pre-Cut design makes application straightforward even for beginners. By following the precise shape of the internal frame, it prevents messy liquid glue overflow and ensures the adhesive stays only where it’s needed, keeping your internal components safe and clean. - Durable Sealing & Buffering. The internal black PE foam core acts as a critical barrier against dust and provides essential impact buffering. Pro Tip: While our material is designed for sealing, a successful water-resistant result depends on a completely residue-free frame and a perfectly flush installation. - Double Security with 2-Pack Bundle. Each order includes 2 sets of pre-cut adhesives. This gives you a risk-free backup in case of a first-time alignment error. We recommend using a heat gun and firm pressure for 30 seconds to fully activate the pressure-sensitive bond for maximum security. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B09DF2TR5J | | Additional Features | 3-Layer Sandwich Structure, Shock-absorbing, Pre-cut | | Best Sellers Rank | #49,239 in Cell Phones & Accessories ( See Top 100 in Cell Phones & Accessories ) #147 in Replacement Cell Phone Backs | | Brand | PHONSUN | | Color | Black | | Compatible Devices | Samsung Galaxy S21 Ultra 5G | | Compatible Phone Models | Samsung Galaxy S21 Ultra 5G | | Customer Reviews | 4.2 out of 5 stars 96 Reviews | | Enclosure Material | PE Foam, Acrylic Adhesive | | Finish | Solid Black | | Manufacturer | PHONSUN | | Material | PE Foam, Acrylic Adhesive | | Model Name | Samsung Galaxy S21 Ultra 5G | | Number of Items | 2 | | Number of Packs | 2 | | Pattern | Solid | | Shape | Pre-cut Precision Contour | | Size | Samsung Galaxy S21 Ultra 5G, 6.5 x 3.0 inches | | Special Feature | 3-Layer Sandwich Structure, Shock-absorbing, Pre-cut | ## Product Details - **Brand:** PHONSUN - **Color:** Green - **Compatible Devices:** Smartphone - **Compatible Phone Models:** Samsung Galaxy S21 Ultra 5G - **Special Feature:** Screen protector ## Images ![Replacement Back Battery Door Adhesive for Samsung Galaxy S21 Ultra 5G SM-G998U G998U1 G998 - Pre-Cut Double Sided Glue Tape Sticker - 2 Pack - Image 1](https://m.media-amazon.com/images/I/31R-RbA18kL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Perfect fir and adherence *by D***R on August 18, 2026* M6 samsung s21 ultra overheated while playing a game. This caused the sealant to fail resulting in a loose backglass. After cleaning the residual off, this installed easily. I compressed the phone over night and found it perfectly adhered. I highly recommend it. ### ⭐⭐⭐⭐⭐ Excelente producto *by A***S on August 24, 2026* Excelente producto ### ⭐⭐⭐⭐ Adhesive sizing is slightly off but it works *by P***A on October 30, 2025* It works but sizing is slightly off and adhesive quality feels low. ## Frequently Bought Together - PHONSUN Back Battery Door Cover Adhesive Tape for Samsung Galaxy S21 Ultra 5G SM-G998U G998U1 G998 (Pack of 2) - iParto Charging Port Replacement for Samsung Galaxy S21 Ultra 5G G998U Charging Port Replacement Kit for 6.8 inch Galaxy S21 Ultra SM-G998U SM-G998U1 USB Flex Dock Connector Replacement - Perzework Rear Back Glass Replacement for Samsung Galaxy S21 Ultra 5G with Pre-Installed Adhesive and Repair Tool Kits (Phantom Black) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.gr/products/378663409-replacement-back-battery-door-adhesive-for-samsung-galaxy-s21-ultra](https://www.desertcart.gr/products/378663409-replacement-back-battery-door-adhesive-for-samsung-galaxy-s21-ultra) --- *Product available on Desertcart Greece* *Store origin: GR* *Last updated: 2026-10-19*