something reserved for saddlery i.e. holsters & bags? All the Heiser logo snaps on sheaths I have seen have the nipple type snap but I better go look. I have seen the nipple snaps on holsters also.

From the auction:

"The strap attached brass/steel combination convex surface brass snap button fastener has the embossed triple H center design logo with HEISER DENVER stamped around the circumference. The snap fastener assembly was made by the U.S. Fastener Company with the holster body fastener portion of the assembly being made of brass."

I don't think I have ever seen a Heiser RMK sheath snap actually made of brass. I think it is brass plated to inhibit corrosion. Brass would be too soft.