Black synthetic rubber conforms to MIL-G-3036. Flexible, hot oil and coolant-resistant grommets. Used to protect tubing, wiring, and control cables where they pass through bulkheads and fire walls. Note: MS35489 grommets and AN931 grommets of like dimensions are interchangeable. Grommet has a groove width of 1/16".
This is nearly identical to my first pilot logbook, but with a new smooth matte black cover. This logbook checks all the boxes from student pilot through Commercial. It might just be the only logbook you’ll ever need. Fly safe!