American pressure suit, tested 1957. MB-1 & 2 were experimental test pilot's partial pressure suits using the K-1 helmet.
Status: tested 1957.
Chest and abdominal bladders were added to produce the G4A anti-G suit for the Air Defense Command, which provided 5-6 protection to 30 km, used no capstans, and with the MA-1 helmet rather than the K-1.