This pre-assembled module will save you time, all packaged into a small yet reliable form factor. It's simple to connect and configure to your needs. Many trucks and boats use 24V systems. These converters will allow you to run a reasonably sized 12V car-stereo or other devices from a 24V supply. Heatsink (not included) should be used for superior performance. Features include: short-circuit protection and thermal cut-out. Many trucks and boats use 24V systems. These converters will allow you to run a reasonably sized 12V car-stereo or other devices from a 24V supply. Heatsink (not included) should be used for superior performance. Features include: short-circuit protection and thermal cut-out. Heatsink: 50 x 100 x 30 mm (rec. size) use Cat. HH-8572 or similar