Stringy thing to stop a garmin or diabolo getting lost it falls off the mount

Lanyard.

edit - here you go, even found on on eBay for you. I imagine the cheaper and non-branded ones are equally as effective.

Ta. does the bit at the end that is a slim string have a separate name?

Don't know. Suspect not as it's just part of the main lanyard.

I'd google for a "Garmin edge safety lanyard" or "Garmin edge tether"

Our daughter just uses an old camera lanyard we  have had lying about. She has busted a few mounts over the years from crashes when racing. The safest place she found to mount it was on the top tube just in front of the seat tube using a 76 Projects Enduro Mount

https://76projects.com/products/enduromount?variant=43190395863256&currency=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=Cj0KCQjwwYSwBhDcARIsAOyL0firQKMUXwjJAsPou719el6ZgXlWN5wlti5L_OuqF81OITyt55UZgnUaAiCLEALw_wcB

I think the lanyard comes with the Garmin. I've been using a Garmin branded one since knocking my Edge 800 out of its mount a few weeks after getting it. Luckily noticed within a few seconds of it falling off and went back to retrieve it.

I found an Edge on the trail at Whinlatter last week, still attached to the snapped bar mount! Handed it in at the bike shop and they seemed to know who it belonged to.

Putting it up against the seat tube surely means you can't really see it, so you might as well just zip it safely inside a pocket?

A lanyard like those above has saved my helmet-mounted Diablo lots of times. I'm forever forgetting to duck enough for branches etc.

I've got a CooSpo GPS unit that doesn't have anything to attach a tether to - any suggestions for how to add a tether point to a device that doesn't have one?

Garmins have the little bit you can loop a lanyard into, but the device I've got has nothing.

Lens keeper things Linky

Thanks @kevgeorge, from your link I then searched and found these action camera tether strap mounts - my thinking being these would cope with more weight. But I've ordered the lens keeper things as there's not much space on my GPS unit to stick a tether to.

Thanks all.

What about one with a loop long enough to go around a diablo and with a clip attachment to release from the thicker, longer lanyard bit ?

I managed to snag the light and this broke the thin fabric, so not ideal as whilst it was tethered this failed at the same time it became detached. On the flip side better than being hung by my helmet!

Diablos ship with a lanyard. Contact Exposure to buy another?

@a11y yes, space is an issue, I use one from the link I posted on a Varia unit, just as insurance over the rubber band mount.

Buy a small reel of 2mm cord and make bazillions of them. Somewhere like ropesdirect.

Exposure have them for sale here:

https://www.exposure-use.com/Brands/Exposure-Lights/Products/Bike/Accessories/Neck-Lanyard-EXPLANLSALES

Also worth getting a brightly coloured rubber guard for it, makes it easier to find if it does come off. You might lose bike-cool points, though.