Not rubber, but if I didn't already have the Snoopy strap for my 1861 I would buy one of these.
https://artemstraps.com/products/loop-less-black-sailcloth-watch-strap-with-white-stitching
Review:
https://www.fratellowatches.com/artem-sailcloth-loop-less-strap/
This is a new OMEGA rubber strap made specifically for 3861 (2021) Omega Speedmaster Moonwatch case. It has moon craters embossed on the inside to keep the moon scheme, outside looks like standard dubber for SMP300. Same strap is used on Moonshine Gold "panda" moonwatch ref. 310.62.42.50.99.001, now available as separate purchase at Omega Boutiques.
