3D printed. This is a part for attaching KATO couplers (close-coupled type) to TOMIX, Greenmax, Micro Ace, etc. TN couplers are expensive! I want realistic coupling faces and spacing! This product is recommended for those people. When using, you may need to cut a part of the product, as with the installation of TN couplers. This product includes 200 pieces. We also sell other quantities. Please feel free to contact us via the question box if you would like to purchase a different quantity, and we will list it. Separately, KATO product 11-731 is required, and assembly is necessary. Depending on the track environment (sharp curves, layouts with gradients, etc.), you may need to use 11-730. We also sell pre-assembled products with all couplers attached, so if you find the processing troublesome or are not good at it, please purchase those. You can add more pieces or purchase in bulk at a great price. Please feel free to contact us.