This is a replacement leg clamp for the "Heavy Duty Alt-Azimuth" tripod by Celestron (Item #: 93607). It turns out “heavy duty” was a bit of an over statement. I got one of these tripods from an auction site as an Amazon return to use as a travel tripod for my 80mm refractor. One of the leg clamps was broken. I designed this as a replacement. It uses the knob and threaded insert from the original one. The old rivets have to be drilled out and replaced.