Totally enclosed. Protected from the elements. Vacuum generator built-in. Regulates boat air line pressures as high as 250 psi, down to a usable 0 to 70 psi. Consists of a regulator 0-100 psi, vacuum generator, control valves for flow in and out, gauge for set pressure, VAC-PRESS gauge for line out pressure/vacuum, handle for carrying and for switch/valve protection, quick connect fitting for boat air hose, hose 11 foot long, to shaft seal emergency air bladder connection. Self test plug on bottom. 2 Vacuum buttons, intentional 2 hand operation to eliminate accidental switching.