The 93-6127 796-801289-001 MKS Vacuum valvehave a small footprint that fits easily into existing, and new, vacuum systems. A formed stainless-steel bellows prevents outgassing, virtual leaks, and particle entrapment between bellows convolutions that extends the valves life cycle over a conventional O-ring shaft sealed valve. The bellows' stroke length is optimized to assure a long cycle life while maintaining high conductance.