... :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 serialD is the position of the handle (looked from ... the positive direction)"D"is the right handle,"E"is the left handle.A is the diameter of roll,Uni:mm ... .0/2.4the drawing of the P504A: Plastic casting feed frame