It is not recommended to use a metal coupler directly on a metal surface or in a metal draft gearbox to avoid possible electrical crossover and shorting that may cause damage. Use the provided insulated gearbox or insulated #21 coupler.
#141 Whisker Metal Coupler Features: Material - Metal, Shank Length - Long (25/64") (center hole to back of coupler head), Coupler Offset - Underset, Knuckle Spring - #622, Centering System - Whisker, Head - Standard Head, Works In Place of - #21, #31 (#141 in a #252 box), long underset "clone" couplers, Works With - NO.5, #58, 20-Series and 40-Series, All Whisker Couplers.
The #141 Kadee Magne-Matic Whisker Coupler features a Metal Coupler, Metal Whisker Centering Spring, insulated Draft Gear Box and Lid. The #141 Coupler may be mounted with supplied 242 draft gear box or with manufactures cast-on coupler pockets. It is not recommended to use a metal coupler directly on a metal surface or in a metal draft gear box to avoid the possible electrical crossover or shorting that may cause damage. Use the provided insulated draft gear box. Includes two pair per package.