Package Includes: (50) Pair #158 Scale Whisker Metal Couplers - Medium Centerset Shank (Extra) #622 Knuckle Springs #158 Whisker Metal Coupler Features: Material - Metal Shank Length - Medium (9/32inch) (center hole to back of coupler head) Coupler Offset - Centerset Knuckle Spring - #625 Centering System - Whisker Head - Scale Head Works In Place of - NO.5, #58, #28, #38 (#148 in a #252 box), #118, #119, & medium centerset inchcloneinch couplers Works With - #213, #232, #234, #242, #252, #262, & most manufacturer cast-on coupler pocketsx (molded-on gearbox). xNote: Some manufacturers now produce models with non-industry standard coupler pockets (molded-on gearbox). These shallower coupler pockets may require slight modification to the gearbox or coupler to function properly. If the model has a shallow molded-on gearbox, the top of the #158 Whisker coupler shank may be filed thinner to fit the shallower cast-on coupler pockets.