New in our product line is this vise block for AR15s. It is being inserted into the mag well like a standard magazine and can then be used to clamp it to a vise to work on the gun or the lower receiver. This is perfect for cleaning, or when completing lower receivers.

The vise block can be inserted from the upper side when the upper receiver has been removed, so any work on the lower receiver can be done upside-down.

(and no, the lower receiver in the pictures is not a real full auto lower, it is a finished 80% polymer lower that came with the text engraved though...)