D System - Keg Coupler - Tap w/ Plastic Probe "D" system is the most common system available in the US, also known as American Sankey. It is used by all the major breweries - Anheuser-Busch, Miller, Molson-Coors, and Labatt as well as most craft breweries. Visit our beer system listing for an expanded listing of beers that use the "D" system valve. Do all brands of beers use the same keg tapping equipment? The keg coupler connects to the keg valve, "tapping" the keg. Both the gas line from the CO2 tank / regulator and the beer hose to the beer faucet attach to the coupler. Beer Keg Coupler Features: Plastic probe for use with acidic products Tin/Nickel alloy plated body improves durability and resistance to chemicals Specifications: System"D" (American Sankey) Handle ColorBlue Handle TypeLever Gas Port3/8" O.D. Barb (To fit 5/16" I.D. Gas Hose) Beer Port7/8"-14 Thread (U.S. Beer Industry Standard) Height3-7/8"