This is the Kriss Defiance 25 round factory magazine for the DMK22 rifle series.
A close copy of the Black Dog Sonic X magazine design with the addition of a rear button lever to activate the Kriss last round hold bolt hold open mechanism.
Will fit any common CMMG / Ciener format AR15 .22 version as well as the Kriss Defiance DMK22.
Manufactured from tough glass filled polymer it is fully strippable for cleaning and will accept Black Dog springs if ever you need replacements.