I used a 3in. extender from HomeDepot They come sized every 1/2 in. Hope that will help Tommy Mc About a buck fifety.I just got a shadetree top and want to extend the handle. Does anyone know if the plastic knob is threaded on and what size thread is it? I did not want to bother butch with this if i did not have to. I haven't tried to take it off yet did not want to tear it up.