I managed to get one from Innodive for my OSTC Plus (they requested a copy of the Heinrichs Weikamp invoice) ; not sure they still have the one for OSTC 3, smaller.
This protection is essential since the surface of OSTC with alloy body is very fragile and quickly marked with scratches.
Heinrichs Weikamp should propose it
Didier A. Defay
OC trimix instructor / ART CCR diver
OSTC Plus #16077
- OSTC 3+ #4806
-- OSTC 3 #3999