Signal Dynamics Back Off XP Brake Light Modulator 01004Compact, solid state electronic module converts brake lights into two choices of visual alerting signals when brakes are applied Mode one emits three short flashes followed by one long flash (3. 5 seconds); repeats as long as brakes are applied Mode two emits five short flashes followed by a steady on light; light remains on until brakes are released Specifications: 12V DC, max. capacity 10A, sealed weather resistant heat sink case, 21 4in L x 5 8in H