Discontinued by Plinker Tactical (2013).
This is the Plinker Tactical load assist tool magazine for the Plinker Tactical 35 round M&P 15-22 fit magazines.
It makes all the difference when loading the magazines.
The loader pushes down on the rear bolt-hold-open tab allowing you full length load assist, which can otherwise be a thumb bashing chore for the last few rounds.