Electronic Transformer available in 60 watt and 150 watt models. Surface mounted for installation at end of track or remote. Knockouts at each end for track sections. Live End Connector (SLE) is required for each track section to be energized. 150 watt model (SST-150 E) is 8 1/4" Lenght 2 1/4" Width and 1 5/8" Heght. 60 Watt model ( (SST-60E) 5 7/8" Length 1 1/2" Width 1 1/8" Height