depends on the hose size (mine was labeled on the hose) - if you had to guess i would go with the 5/16 size bulb - that is what I put on mine and i have 1/4 line currently. I just put a little 2 cycle oil on the ends it it slid in with a little effort. I think 5/16 would with with 1/4, 5/16 or 3/8 line as long as you get some of the stainless clamps that screw tight