its a 18650 battery wrap, cant remember where from.

you can find it online pretty easily

https://m.banggood.com/5Pcs-Halogen-Free-21-Heat-Shrink-Tubing-Transparent-Wire-Cable-Sleeving-Wrap-p-1182650.html?rmmds=search

not that, similar to this one:
https://banggood.app.link/auAwNLP1yV
try amazon or ebay

yup i got my clear heatshrink from amazon too

thanks, bud!

they're surprisingly good, same performance with my brotherhobby r5 motors, smooth and powerful. Also had a couple of hard crashes, head on to the gates and trees, they are still working fine, best value motors for me but lets see how long they'll last.