[h4waii]

https://www.thingiverse.com/thing:5254286

Get one of these tiny cases printed, glue it to the inside of a NATO watch strap, or you can forgo the case and see how it holds up.

[jqpabc123]

That looks interesting but more complicated than mine. Mine is basically added in-line with the watch strap. The strap itself is unaltered.

The card slides into a slot in the side and latches into place. SD cards are designed with a latch key just for this purpose.

[h4waii]

Can you share a photo?

I keep 3 (!!) RFID tags on my wrist using my Pebble 2SE and a NATO strap, they're 100% unnoticeable and invisible aside from added functionality.

I'd love to add storage for microsd to it; especially if it doesn't impact my current method

[jqpabc123]

I doubt it would be of much benefit. It is black plastic (to match the watch band) so it doesn't photograph very well.