This is an early, complete, pre-production prototype of a Model 800 slide action shotgun, a model that was never released to the public. The serial number on this particular example suggests that it may have been the first testable prototype, and a tag on the receiver marked "M800 16GA/RETURN TO/WORKING/CONDITION" and signed with initials "BS" may indicate that this prototype malfunctioned during testing. It has a single bead sight on the barrel marked "WINCHESTER-MODEL 800-16 GA.-2 3/4 CHAM./MADE IN U.S.A.-WINCHESTER PROOF STEEL/FULL". The underside of the receiver is marked "MODEL 800/000001". Smooth extension slide handle and pistol grip stock with vented Winchester recoil pad. The right side of the buttstock is marked "SLAVE" in yellow paint. The included FN America Certificate of Provenance identifies the shotgun by model and serial number, stating that is was previously a part of the Winchester Factory Collection where it was maintained by U.S. Repeating Arms.