Hey there, classic car and Jeep owners! This KAC brake master cylinder (part number M56193) is a brand-new replacement, not remanufactured, so you're getting fresh parts with no worn-out internals. It's made from durable HT200 grey cast iron to match the original's strength. Fits a ton of cool old vehicles—think 1970-1974 AMC Javelin, 1970-1976 Gremlin, 1970 AMX, and Jeeps like the 1970-1975 CJ5, 1976 CJ7, and 1970-1973 DJ5 (check the full list to be sure!). It's a two-outlet design with a 1-inch bore, and yes, the reservoir is included. Super important: always use the 'Amazon Confirmed Fit' tool at the top of the page and double-check your vehicle's year and model, plus those OE numbers like 2536237 or 8125743, before you click buy. Keeps your braking system solid and safe.