Kadee HO Scale #308 Delayed "under-the-track" Uncoupler Under the track "hidden" installation. A permanent magnet and steel intensifier plate are included along with instructions. Suitable for a variety of scales from HOn3 to O-Scale. #308 Under-the-Track Hidden Delayed-Action Magnetic® Uncoupler - HO, S, On3, On30, O Scale Delayed Magnetic Uncoupling HO, S, On3, On30, O-Scale Uncoupler Under-the-Track Under-the-Track "hidden" installation. A permanent magnet and steel intensifier plate are included along with instructions. Suitable for a variety of scales from HO to O-Scale. Track not included O-SCALE: Because of the thicker ties and higher rail in O-scale it will be necessary to use 2 or 3 magnets stacked together and one steel intensifier plate on the bottom of the stack. On some track you may need to trim the bottom of the ties to fit the magnet(s) closer to the rails. Contains: One Delayed Action Magne-Matic® Uncoupler & One steel intensifier plate One per package UPC: 765484003083 USA Flag Made in the U.S.A. HO Scale S Scale On3 Scale On03 Scale O Scale Package Includes: (1) each #308 Delayed Action Magne-Matic® Uncoupler Magnet (1) each Steel Intensifier Plate #308 Dimensions: Magnet Dimensions - 2"L x 1 1/2"W x 3/16"H Intensifier Plate - .045" thick