38 Couplers - Medium Centerset Plastic Shank This industry leading coupler features plastic standard coupler with metal knuckle, and #621 torsion centering spring and comes complete with #233 insulated draft gearbox and lid. The #38 Magne-Matic® Metal Coupler is designed mostly for body mounting with limited space either above or below the mounting platform, with or without Draft Gear Box Lid and with Draft Gearbox Lid either on top or bottom. Note: The 30-Series Torsion Spring can be mounted either below or above the coupler shank, but must always be mounted between the Coupler Spring Lid and Draft Gearbox. The 148 Whisker® Metal Coupler mounted in a #252 Snap-together Gearbox is equivalent to the #38 Coupler. The Whisker® Coupler mounted in a #252 Snap-together Gear box makes for simple and easy assembly. Other Whisker® Coupler #38 equivalent options include #158 Whisker® "Scale" Metal Coupler, #118 "SF" Shelf Whisker® Metal Coupler, and #119 "SE" Shelf Whisker® Metal Coupler when mounted a #252 Snap-together Gearbox. 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. Refer to our helpful Coupler Conversion Charts to determine the appropriate coupler to use on your model. Two pair per package Package Includes: (2) Pair #38 Plastic Shank Couplers - Medium Centerset Shank (2) Pair #621 Torsion Centering Spring (2) Pair #233 Gearboxes & Lids (2) Pair #210 Washers (2) Pair #256 - 2-56 Screws (2) #622 Knuckle Springs #38 Plastic Coupler Features: Material - Metal Knuckle, Plastic Coupler Shank Shank Length - Medium (19/64") (center hole to back of coupler head) Coupler Offset - Centerset Knuckle Spring - #622 Centering System - Standard Shank Centering Spring - #621 Torsion Centering Spring Head - Standard Head Works In Place of - NO.5®, #28 or #58 coupler can be used in #233 draft gearboxes Works With - #233 draft gearboxes #233 Plastic Draft Gearboxes & Lids Features: Material - Insulated Plastic Dimensions - 3/8"L x 5/16"W x 9/64"H Works With - NO.5®, #58, 20-Series Couplers #38 in a #233 monted on top. 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) #38 in a #233 monted on bottom. Mounting Specifications: Mounting Height - 29/64" Centerline - 25/64" Trip Pin Height - 1/32" Center Hole - 2-56 Insulated Screws are the most commonly used. (Screw length will vary) WARNING: CHOKING HAZARD - Small Parts - Not for children under 14 years. Kadee Quality Products Co. products are not toys and are not intended for children under 14 years old.