The ARS-3 shares the same rail interface as the SMB and the LMB Accessory Adapter. Two ball-pressure pieces on each side of the rail prevent an attached Accessory Rail Bracket ARB-1 or the ARC-1 from slipping off. It is compatible with all 3/8-16” interfaces which offer holes for the two securing pins. A slotted hole extends the application area and allow it to move the rail into the desired position. Uniquely, four different sizes of hex key can be used with the Accessory Rail Small-3 without having to adjust it - 3,4, 5 and 5/32 will all fit perfectly.