The J-Arm adapter is one of the components used to mount a night vision device on a helmet; it attaches to the Wilcox L2G20, Wilcox L2G24 and Wilcox L4G24 platforms. It is compatible with night vision monoculars, including the AN/PVS-14, PVS-14-XLS and Night Enforcer.

The Wilcox J-arm mount is designed for use with AN/PVS-14 series night vision monoculars and their equivalents, utilising a dovetail-type connection. This mount is compatible exclusively with Wilcox or Norotos mounting systems, in addition to traditional USGI bayonet mounts. The device allows for adjustment of height and angle, as well as positioning in front of either eye. A special button on the mount allows the mechanism to be unlocked and the monocular to be rotated by 110 degrees. All components of the mount, including the connectors, are made from sturdy steel.