Fits 1, 2 hp DentalEz single models, Apollo 1 hp, 1.5 single & tandem models, Air Techniques-Vacstar models Ohmeda-Matrix most models, Turbine Industries, Techwest-Whirl Vac models, Vacudent-Workhorse single , Midmark® CV3R plus a number of other units Thread ID = 2-3/8in (Qty 12) - #2200