The product is a quantity of 100 Caddy 4BRT32 briddle rings with a 2" diameter and a 1/4-20 thread size. Manufactured by Nvent, these drive bay caddies are designed to hold 4 optical drives in a vertical orientation, making them ideal for organizing and accessing drives efficiently. The 1/4-20 thread size allows for easy mounting and securing of the caddies within a drive bay. This product is essential for maintaining a tidy and functional storage solution for optical drives in various computer setups.