This tool should be used as a guide only. Hardtop XP may not be an exact match for Carbothane 134 HB by but we have given the closest match we can. Hardtop XP should do the same job and have similar properties but you should always read the technical data sheets for both Hardtop XP and Carbothane 134 HB to be sure. Please see any notes to see any major differences and call us on 01285 862132 if you have any specific questions.