Many round-body (“Ponton”) Mercedes-Benz models of the 1950s and early 1960s, as well as early designs of the Unimog 404, use a sealed bypass thermostat housing design, which does not allow the thermostat element to be replaced when worn out, or switched out for hotter or cooler thermostat elements as needs demand. Original design thermostat housings for these cars can sell for over $400–when they are available at all–and they remain a disposable design, without a replaceable element. We are now offering a Ponton version of our exclusive, precision machined, billet aluminum updated thermostat housing, designed for ease of service, and longevity. This is the same design as our updated thermostat housing for 300 and 300SL, with smaller, 32mm diameter inlet and outlet ports to fit a wide range of carbureted round-body Mercedes cars and Unimog 404 of the same period. The threaded sections of this housing can be easily disassembled, allowing the standard 55mm (190SL type) thermostat element to be replaced or exchanged in minutes. This is the same diameter thermostat element used in the original Behr and Wahler bypass thermostats, and because our housing is built around a universal element, we can supply thermostats in a full range of temperatures. If you do not see the temperature range you need, just ask. Early Ponton cars have an M18 machined fitting on the bypass outlet; later cars, as well as early Unimog 404 models, use a 12mm beaded hose barb instead. We have designed this thermostat housing with a universal bypass port, which will allow us to supply either hose barb or threaded bypass fittings as needed. A Brooklyn Motoren Werke, Inc. exclusive. Prototype 300SL unit pictured. Appearance of round-body units may differ slightly.