... :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 ... right handle,"E"is the left handle.A is the diameter of roll,Uni:mm "A"means the roll diameter is ø30 ... .0/2.4the drawing of the P504A: Plastic casting feed frame