... :P504A-BV1.0/1.2 P means plastic feed frame,casting feed frame without "P"504 is the code for wire feed ... frame we have 21,401,402,404,501,502,504,P504 ... of roll ,Unit:mm the figure same as the welding machine diameter,we can change it for you,The feed -roll ... .0/2.4the drawing of the P504A: Plastic casting feed frame