This is the large selection knob on the ULXP4 receiver.

These seem to come off easily, and are frequently missing for some reason.

Get the genuine Shure replacement here for cheap, and restore the front of your ULXP4 receiver.

NOTE: USPS now requires these to be shipped as a package, so USA mailing cost is now 6x what it           was. So, 6 knobs (or more) ship for the same price as one, but I have no way to reduce the price             of just one. Also the price varies with location, so I'll let eBay calculate.

  So far, international postage has not changed.