Package Includes: (25) Pair #148 Whisker Metal Couplers Medium Centerset Shank Extra #622 Knuckle Springs #148 Whisker Metal Coupler Features: Material Metal Shank Length Medium (9/32) (center hole to back of coupler head) Coupler Offset Centerset Knuckle Spring #622 Centering System Whisker Head Standard Head Works In Place of NO.5, #58, #28, #38 (#148 in a #252 box), #118, #119, #158, & medium centerset clone couplers Works With #213, #232, #234, #242, #252, #262, & most manufacturer caston coupler pocketsx (moldedon gearbox). xNote: Some manufacturers now produce models with nonindustry standard coupler pockets (moldedon gearbox). These shallower coupler pockets may require slight modification to the gearbox or coupler to function properly. If the model has a shallow moldedon gearbox, the top of the #148 Whisker coupler shank may be filed thinner to fit the shallower caston coupler pockets.