AREA 419 ARCALOCK Fixed Barricade Block Developed for use on our flat ARCALOCK rails such as the 12″ Universal, M-LOK, Keymod, and MPA that do not have a built in stop. The block uses a pinch clamp design and also a set screw to engage one of the ARCALOCK cuts to guarantee no slippage. A 3/32 Wrench... See More