... is the diameter of roll,Uni:mm "A"means the roll diameter is ø30,"B"means the roll diameter is ø40V is ... the type of roll ,we have V ... aluminium wire0.8/1.0 is the trough dimension of roll ,Unit:mm the figure same as the welding machine ... can change it for your welding wire size. Our standard feed-roll size:0.6/0.8,0.8/0.9,0. ...