You mean the small knobs. I have a couple RBM junker chassis in my van right now. No one at the hamfair wanted them for free, altho someone did buy the ggod condition RBM - HF. When i go out later today i'll see what knobs are on them. The only difference in receivers is the RBS tune and band change knobs have the engraved glow in dark letter. ( radium ? )