OTP key generator lanyard ID card holder (to suit SafeNet OTP 110)

My employer recently introduced 2 factor login for our IT systems and we were issued SafeNet OTP 100 key generators.

These tend to get fastened to our lanyards (credit card sized ID Card Holders) - but they rattle when you move around and are a general nuisance.

I've designed this holder to fit the open syle ID card holders (see photo).

I printed with 0.15mm layers in PLA (add a small amount of support for the wider side of the recess), and it fits perfectly.

NEW - Added a more curved version with reinforcement webs.