Keystone KTET-75-1-SCP-DIM-HV-AL 12 Volt dimmable transformer ballast brings 120V down to 12V to operate halogen lamps that are 75W or less. This model has rear studs and mounts to a J-Box. Keystone?s portfolio of durable low-voltage halogen and xenon transformers are ideally suited for both track lighting and recessed lighting applications. Chosen by the leading designers and architectural fixture manufacturers for reliability and performance, all Keystone low voltage transformers are 100% factory tested to ensure superior performance in the field. Warranty: 3 YearsKeystone Technologies