Listed below are the different types of tremolo back covers. These back covers can come in varying degrees of quality and colors. The screw patterns may be different than what are on the body you have, so keep an eye out for that!
Mexican Bridge Covers
Cost: $3 to $5
Mexican Strat Standard covers usually only come in white. Also there is a difference between right and left handed covers.
American Bridge Covers
Cost: $10 to $15
American Stratocaster Covers are used interchangeably between all American models and fit Mexican models. There are many different colors which vary between an American and Deluxe.
Deluxe Bridge Covers
Cost: $10 to $25
Deluxe Strat tremolo covers are made from 3 ply parchment and come in many colors. This is a great and easy way to ad style to your Strat.
Custom Shop Bridge Covers
Cost: $10 to $20
Custom Shop Strat back covers have a vintage look to them. They can vary in color, but most are tan. They also are not beveled liked the regular American covers.