#119 SE Metal Shelf Whisker® Magne-Matic® Coupler Medium 19/64 in Centerset Shank with #242 draft Gearboxes 2pr - Kit. The #119 Kadee® Magne-Matic® Coupler features a Metal Coupler, insulated #242 Draft Gear Box and Lid with center screw holes for mounting. Shelfs actually work. The #119 Coupler may be mounted with supplied #242 draft gear box or with Manufacturers cast-on coupler pockets. Two pair per package 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 .