Get one from Newport Engineering. That's what I'm unsing, works great and fit very well. I opted for the delay switch option, which is nice to have. The stock knob worked fine, but I did have to make a bushing to make it fit tight. Brass tubing, sourced from the local hobby shop, worked very well for that. Either switch will also give you the option of adding a washer pump if you want, it was the extra wire to run it. I got mine from Patrick's.
