DarcoPTQ Series PegAssist Insole is Designed to Fit the Darco Square Toe MedSurg Shoe

My XL came with a black, lightly padded insole that has material around the heel with a self stick backing. what is if for? Nothing in instructions

Can you trim these?

Will the x-large fit my 15 eee foot ? i need to know before i order it..

Is this for a mens size 13 boot or Hospital shoe ?