Product #: 39 Product Line: Kadee Scale: O Scale Package Includes: (2) Pair #39 Plastic Shank Couplers - Long Overset 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 Refer to our helpful Coupler Conversion Charts to determine the appropriate coupler to use on your model. 30-Series Coupler Instructions30-Series Chart #39 Plastic Coupler Features: Material - Metal Knuckle, Plastic Coupler Shank Shank Length - Long (25/64") (center hole to back of coupler head) Coupler Offset - Overset Knuckle Spring - #622 Centering System - Standard Shank Centering Spring - #621 Torsion Centering Spring Head - Standard Head 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 #39 in a #233 gearbox on top. Mounting Specifications: Mounting Height - 35/64" Centerline - 25/64" Trip Pin Height - 1/32" Center Hole - 2-56 Insulated Screws are the most commonly used. (Screw length will vary) #39 in a #233 gearbox on bottom. 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 Multi-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) #1020 Coupler & Special Purpose Tweezers