I've got two Lyman Lube sizers, One says 4500 the other says 450, however they are both Lyman brand, one is orange the other is gray, they both do the same identical job, however one has the Midway Heater in which I use the hard lubes; which I prefer for modern bullets such .380 thru .45acp, however the other one I use the Alox lube, and SPG for the older cartridges such as 45-70, in Springfield Trapdoor and my Sharps and .45 Colt, 44-40 etc. I'm sure the RCBS is of equal quality, however when I was in the market for such equipment Lyman was the only in stock item I could find.