BlackStar DS100A13H 2 7/16 K2S - Double-Single 100 Pitch A-Plate Sprocket - 13 Tooth - 2-7/16" Bore Bushings The D&D Global 350-S8M-856 is

The D&D Global 350-S8M-856 is a synchronous timing belt with S8M-pitch profile

"mpn":"30AT5/330US-D&D"

so a 12/C125 from any major manufacturer shares the same dimensions and runs on the same pulleys/sheaves

The Bando 8PK1910 Automotive Serpentine Belt is a Micro-V (multi-ribbed) belt with Micro-V ribbed PK-section dimensions

BlackStar DS100A13H 2 7/16 K2S - Double-Single 100 Pitch A-Plate Sprocket - 13 Tooth - 2-7/16" Bore Bushings The D&D Global 350-S8M-856 isThe BlackStar DS100A13H 2 7 16 K2S is a 100 pitch double single strand A Plate roller chain sprocket with 13 teeth, precision manufactured from SAE 1045 steel and features machine cut tooth profiles for smooth, reliable chain engagement. This sprocket has a 2 7 16" bore and is ready for immediate installation. Specifications Part Number DS100A13H 2 7 16 K2S Chain Pitch 100 Number of Teeth 13 Bore Size 2 7 16" Bore Type Plain Bore Hub Style A Plate