Supreme Instruments Corp. 40 Tube Checker Get a print! $8.00 Add to Cart Product Information: Model:40 Tube Checker Manufacturer:Supreme Instruments Corp. Schematic Pages Page 1 Schematics Content Page 1: MODEL 40 TUBE CHECKER SUPREME INSTRUMENT CORP. Please note: we carry a wide range of products which will fulfill the specifications above. Please use our search function or browse our products to find what you need!