3D printed. This is a part for attaching KATO couplers (close-coupled type) to TOMIX, Greenmax, Micro Ace, etc. TN couplers are expensive! You 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, just like when installing TN couplers. This product includes 50 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. You will need KATO product 11-731 separately, and assembly is required. We also sell pre-assembled products with couplers already attached, so if you find the processing troublesome or are not good at it, please purchase those. For additional orders, it will be +50 yen per piece, but we will offer a discount for customers who purchase in bulk.