Ametric&reg; #40-1 Half Link (One Roller) for, Stainless Steel, Rivet Type,Single Strand Roller Chain, 0.5 Inch Pitch (P), 0.309 Inch Between Plates (b1), 0.313 Inch Roller Dia (d1), 0.654 Inch Chain Width (I), 08A-1 SS ISO Number, (1-105)