RC GearPro Drone Gimbal Camera Lens Cover Cap Gimbal Lock for FIMI X8 SE RC Quadcopter Drone

It fits & does what it's intended to do. There are a few others that are $'s more, but the basic principle is to protect the camera/gimbal when not in use.

I have 2 of these one for each fimi 18/20 goes on easy and provides good gimbal protection.A little tricky to get off sometimes.