Amazon.com : Osprey Global 22-250-BS Laser Boresight for .22-250 Remington Ammo Firearms. Red Laser (Class IIIA : Power <5mW : Wavelength 635-655nm) : Sports & Outdoors
X-CALIBER Survival-Rifle Gauge Adapter System - Soldier Systems Daily
these are shotgun adapters aka chamber reducers aka shotgun inserts and called by a few other names. they allow you to fire lower gauge (caliber) shotgun shells out of a larger bore