betwwen a 4.5k protoyz preset reg, and a 3k pro toys reg, as i ordered a 4.5k protoyz reg from planet, then filled it to 4500psi at hilton park , it blew its burst disk and turns out it only had a 4.5k HP burst disk in it and am wondering if they sent me a 3k instead??? so need to know how u tell the difference.