I use the Hogue Hand-All #17000 for most of my Kel-Tec grip upgrades. It works fairly well for the SUB-2000 but is a little large at the top of the back strap on the PMR-30, CMR-30 and CP33 but is (IMO) considerably better than not having a rubbery grip and the loose material at the top rear contracts in a day or two. I haven't tried the Hogue #17000 on the RDB and RFB yet, but I should. I think it should fit fairly well, given the size of these grips and the grip angle. There's a Pachmayr rubber grip sleeve that other people like for their Kel-Tec firearms.