ROLLER CHAIN SPROCKET, 

MARTIN   120B16

PITCH,   120  (1-1/2")

NUMBER OF TEETH, 16

BORE,  1-1/4"  **NO KEYWAY OR SET SCREW**  

HUB DIAMETER,  5-1/4"

OVERALL THICKNESS,  2-1/2"

THIS SPROCKET IS NEW OLD STOCK.