The Snapcap or Nipple Protector was issued on many Enfields imported during the Civil War. It is used to protect the nipple and hammer from damage during an accidental dry-fire. Our copy has a top made of hardened rubber, with a 1/4" square socket designed to fit over our correct style square lug, high "shoulder" military nipple. They may not fit other nipples. The 6-1/2" brass chain has a steel ring to secure it to the rifle, as issued with the Enfield Muskets. Will not fit the '42 or '61 Springfield.