Master brake cylinder (aka rear brake pump, main brake pump). Commonly used for (but not limited to) 400cc, 500cc, 700cc and 800cc engines, such as the Hisun 400cc, 500cc 700cc and 800cc ATVs and UTVs as well as many other clones, rebrands and similar displacement machines.

These machines are commonly manufactured by Chongqing Huansong Industries (Group) Co., Ltd. and distributed by a range of exporters, importers and distributors under such brands as: Hisun, Bennche, Coleman, Massimo, Qlink, Menards Yardsport, Big Muddy, Powermax, Nordik, TSC, Rural King, Cub Cadet, Excalibur, US Titan / Supermach, Precision, JMC and many others.

Common Hisun model names are primarily listed as variations of "Hisun HS400 ATV", "Hisun 400cc ATV", "Hisun HS500 ATV", "Hisun 500cc ATV", "Hisun HS700 ATV", "Hisun 700cc ATV", "Hisun HS800 ATV" and "Hisun 800cc ATV" as well as "Hisun HS400 UTV", "Hisun 400cc UTV", "Hisun HS500 UTV", "Hisun 500cc UTV", "Hisun HS700 UTV", "Hisun 700cc UTV", "Hisun HS800 UTV" and "Hisun 800cc UTV". Common Hisun master brake cylinder part number is 44520-115-0000 listed as "master cylinder brake pump" in their parts lists.