Gold - Concentric Stacked Knob Set (Fits CTS Concentric Pots) Concentric Stacked Knob Set (Set Screws) - Gold. Concentric Stacked Knob Set, With Set Screws, Gold. Top Knob - Inside diameter .192", 3/4" diameter, 1/2" tall. Bottom Knob - Inside diameter .272", 1" diameter, 3/8" tall. These fit the CTS concentric pots sold in our store. sent soon.*** Products may have a high price.*** ***Please compare prices before you buy.***