J&M was founded in 1962 by Jon Steffes Sr. and Milo Sieve and is now operated by Mike Sieve(J&M mechanic of 30 years) J&M designs and manufactures the original J&M promini and promagnum sprayer. Specializing in equipment for: Asphalt, Concrete, Drywall, Plastering and Fireproofing (Mixers, Pumps, Sprayers, Blowers, Plate Compactors, etc.) Gas and Diesel Engines.