My Marcel is only 1.5 lbs. right now and I MUST have a collar for his bell (and later for his tag). I use the collar only for those purposes.
This website has FABulous collars:
https://shop.cloescollars.com/splashPage.hg
Plus, you can get the break-away version, which is so great for these tiny creatures...you never know what they'll get into.
Best,
Ann