David Grimes, Inc. 4-DL Get a print! $8.00 Add to Cart Product Information: Model:4-DL Manufacturer:David Grimes, Inc. Schematic Pages Page 1 Schematics Content Page 1: Type 4-DL Inverse Duplex (Reflex) Circuit. 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!