This is the High Tower Armory (HTA) magazine coupler for Ruger 10/22 magazines.
Allows faster mag changes by stacking two 10 round factory Ruger magazines together into single unit.
Ideal for competitions with required mag changes or magazine capacity restrictions.
Works with the following Ruger magazines:
Manufactured from a tough black polymer, the loader clamps the magazines firmly together with a hex bolt fitting and includes a compact 9/64" hex key cleverly stowed away inside.
Superior to push fit designs which can be tugged apart if too much force is applied.