Black Line Power Supplies are engineered and built to work under the heavy use of motor drive shooting, multiple-pop exposures, and long hours. They have custom engineered heavy-duty rocker switches, locking/quick release light unit connectors, and are encased in dust-proof, sealed cases (except the 2401sx, which has fan cooling to increase its duty cycle). Speedotron Power Supplies are backed by a 2-year warranty, with an optional Plus-3 Protection Plan available.