BlackStar 120A45R - 120 Pitch A-Plate Sprocket - 45 Tooth 2.3/4" What does the T10R in

What does the T10R in 10T10/2250R mean

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BlackStar 120A45R - 120 Pitch A-Plate Sprocket - 45 Tooth 2.3/4" What does the T10R inThe BlackStar 120A45R is a 120 pitch A Plate roller chain sprocket with 45 teeth, precision manufactured from SAE 1045 steel and features machine cut tooth profiles for smooth, reliable chain engagement. Specifications Part Number 120A45R Chain Pitch 120 Number of Teeth 45 Bore Type Plain Bore Hub Style A Plate Strand Count Single Material Steel Outside Diameter 22. 35" Pitch Diameter 21. 504" Approx. Weight 88. 800 lbs Cross references: Browning