This industry leading coupler features an all metal coupler head, shank, and Whisker® centering spring and comes complete with insulated draft gearbox and lid. The #142 Magne-Matic® Whisker® Metal Coupler may be mounted with the included #242 Snap-Together Gearbox or with other manufacturers cast-on coupler pockets. 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 #22 coupler. HO-Scale Package Includes: (2) Pair #142 Whisker® Metal Couplers - Medium Overset Shank (2) Pair #242 Snap-Together Gearboxes (2) #622 Knuckle Springs #142 Whisker® Metal Coupler Features: Material - Metal Shank Length - Medium(9/32") (center hole to back of coupler head) Coupler Offset - Overset Knuckle Spring - #622 Centering System - Whisker® Head - Standard Head Works In Place of - #22, #32 (#142 in a #252 box), Medium Overset "clone" couplers Works With - #213, #232, #234, #242, #252, #262, manufacturer cast-on draft gearboxes #242 Snap-Together Gearbox Features: Material - Insulated Plastic Lid Type - Snap-Together Dimensions - 7/16"L x 5/16"W x 1/8"H Works With - NO.5®, #58, 20-Series and 40-Series, All Whisker® Couplers Mounting Specifications: Mounting Height - 1/2" Centerline - 25/64" Trip Pin Height - 1/32" Center Hole - 2-56 Insulated Screws are the most commonly used. (Screw length will vary) Recommended Tools: #206 Insulated Muti-Purpose Coupler Height Gauge #231 Greas-em Dry Graphite Lubricant #237 Coupler Trip Pin Pliers #240 Double Headed Pin Vise #241 Dual Tool Manual Uncoupling Tool and Spring Pick #246 Tap (2-56) and Drills (#50 and #43)