Country of Origin: Made in USA. 

Inner diameter Core Size is 1” (25.4mm). 

Part Number Compatibility: 754473623692, P1037974-012, P1037974012, & All 1" Thermal Transfer Ribbon Cores

Ribbon width should be 1/4 to 1/2 inch wider than the label or label carrier (backing of label). If you go too wide on the ribbon, you run the risk of causing the ribbon to wrinkle. If you go too narrow you will experience a reduced lifespan of the printhead.