Found these new knobs to replace a missing manual RA knob on our Celestron Celestar, would work fine on any Celestron or other brand similar mount where the RA manual adjustment shaft is 1/8". Has two set screws that use a .050 allen wrench (not included).

This knob has a few advantages over stock, especially if you have an early mount with the tiny knob. It's large in diameter at nearly 1" for better control of small movements, the side is angled slightly (see photos) so your thumb rests on it nicely when using it (put fingers on the fork base for steadyness) and it's bright aluminum so you can find it easily in the dark. It's .39" thick so it fits under the movement of the RA lock knob but you should confirm that.

WHO WE ARE: Oddog2 is a husband/wife team, home-based small business specializing in the buying/refurbishment/selling of primarily photographic equipment. We do occasionally have other types of things to sell that come to us as a result of our search for camera-related items. We have 47 years of experience (22 years as a hobby, 25 as a full time effort) with photographic equipment, both as a shooter (17 years newspaper photojournalist) and as a collector/restorer/seller. We have been on eBay as Oddog or Oddog2 since September 1999.