J-arm
A J-arm is a mouting adapter for monocular devices to attach to a mount for hands-free use. Mounting adapters for binocular devices are termed ”bridge”.
J-arms usually consist of a piece polymer or metal having a mount compatible interface on one end and a screw in the other.
Some of these are device or mount specific while others fall under wider systems such as dovetail and bayonet types. The latter is considered a legacy system since the dovetail has become very popular as it presents a less bulky, equally secure and less prone to instability because of wobble/play.
Bayonet[edit | edit source]
This type was the original attachment type which was featured on the Wilcox RHNO (nicknamed Rhino) among others.
Dovetail[edit | edit source]
A newer attachment type that gets its name from using a ”dovetail” bevelled slot reminiscent of dovetail rails for camera and weapons accessories. This soultion has also the added bonus of adjustability if the dimensions are slightly off. The widely popular Wilcox L4G24 mount features this type of system.