The #39 Kadee® Magne - Matic® Coupler is a top - notch product for HO scale models. It comes in a pack of two pairs. This coupler features a super - strong plastic insulated design, equipped with a #621 Torsion Centering Spring and an insulated #233 Draft Gear Box. The 30 - Series Kadee® Magne - Matic® Couplers offer great flexibility in mounting. They can be body - mounted either above or below the platform, with or without the Draft Gear Box Lid, and the lid can be placed on top or bottom. Note that the 30 - Series Torsion Spring should be installed between the Coupler Spring Lid and Draft Gear Box, either below or above the coupler shank.

Using this product is easy. First, decide where you want to mount the coupler on your HO scale model. You can choose to mount it above or below the mounting platform. If you use the Draft Gear Box Lid, you can place it on top or bottom as you like. When installing the 30 - Series Torsion Spring, make sure it's between the Coupler Spring Lid and Draft Gear Box. It can be either below or above the coupler shank. For maintenance, keep the coupler clean. You can use a soft brush to remove any dust or debris. Check the Torsion Centering Spring regularly to ensure it's in good condition. If you notice any damage, replace the parts promptly.