Check the listing for details. Replacement Telescope focus knob Universal 5mm tuner slot. 30mm outer diameter. Color: black, Condition: New. Listed at 8.49 USD. Fine Focus Knob upgrade or replacement knob. Fits any 5mm bar or slotted tuner bar that is under original knob. Knob should have a flat surface and this knob has a set in nut with bolt that tightens down onto that 5mm focus bar. I also make 4mm ,6mm or any other size just let me know the bar diameter. Has set in nut with bolt for tight and secure tuning. Condition is "New". Shipped with USPS First Class Mail. Made and designed from 3D printing software, fitted and tested. Made from Spencer-3D, made in United States. Comes in gold but can have in other colors when requested. Just message if need a different color or need a custom part. This knob is 30mm diameter and is perfect for fine tuning its sometimes hard to do with a small knob. Faster tuning when it counts. 2 to 3 day U.S. shipping.