This is a Lionel # 1008 Camtrol for 027 track. It is a manual un-coupler (no electricity needed). After being attached to the track,(when working properly) a flip of the switch will dis-connect the trains. It is in poor condition. There is broken spring on the bottom, so only one of the flippers are working. Also, it has paint residue, marks, dirt, scratches, and dust. It measures about 3 x 3 3/4 inches.