Listing is for 2 sets. 3/8" length, rubber spacer included. Good general purpose length that works with most hardware. Might be on the long side for thinner setups (use a rubber spacer, or use 1/4" for that), or it could be too short for thicker setups (use 1/2" or thicker for those). Since theres so many hardware attachment options, and sheath thicknesses its up to you to insure you get the proper size.
Industry standard carbon steel with a black oxide coating (not stainless), these are used to attach sheaths to belt loops, Teklok's, straps, etc
The screw: Flat top Truss screws in black oxide steel (not stainless). The Flat-Head Truss is shaped in a way that provides fastening support with the least amount of surface obstruction. The Flat-Head Truss Screw provides a flat surface under the head, which will sit flush and provide a clean look and positive lock.
The post: Slotted back to easily attach and remove hardware. Black oxide steel (not stainless)