The 12.3 Oetiker Hose Clamp best fits a 3/16" liquid hose when attaching a shank stem or liquid keg disconnect. The Oetiker Clamp is the best clamp for attaching hoses. The inner circumference of clamp is free of any steps, gaps or bridges for a no-leak seal. Clamp requires the use of a special tool (OTC - Oetiker Clamp Tool).