Info:Martin 100C10 Type C Single Strand Welded Reboreable Roller Chain Sprocket, 1 to 1-7/8 in Dia Bore, 4.598 in OD, #100 Chain, 10 Teeth, 1-1/4 in Pitch, Steel
Info:Martin 100C11 Type C Single Strand Welded Reboreable Roller Chain Sprocket, 1 to 2-1/4 in Dia Bore, 5.008 in OD, #100 Chain, 11 Teeth, 1-1/4 in Pitch, Steel