The forearm will NOT fit the 2240, 1322, 1377. It will fit the 2260, but look goofy.

THIS IS THE FOREARM ONLY! IF YOU WANT THE BUTT STOCK, IT IS AVAILABLE SEPARATELY.

Optionally available in this listing is the forearm plate and screws.
(What is affixed to the front of the trigger and fastens to
the forearm and also the two forearm screws).

You can also buy it with the band, too, for the full kit.