This listing is for the BTI & Hunter Amplifier, Large Knob Inlay (1)This inlay measures 1 7/8 inches in diameter.They will also fit the Alpha 77 and 77DX Amplifier knobs.I also have a listing with units available which will save a little on the shipping costs.Please see my other listings for knob inlays for many other radio, amplifier and Antenna tuner types.This inlay has a brushed aluminum finish just like the originals, and they have a plastic film on the face side which you have to remove before you instal them.It is very easy to install. You simply put a drop of contact cement in the middle of the back side of the insert and you can glue it on top of the old one, or you can remove the old scratched up insert with a pick.To remove the old one you can drill a small hole in the middle of the old insert to remove it with a sharp tool so you do not damage the edges of the inset area.It makes such a difference to replace the scratched or dinged insert as they are a vocal point of attention.