I haven't worked out what to do with the bleeper bit yet, but the Ancol cat collars were far too big for her. I went out and bought an Ancol kitten collar. Even at its smallest, it is still slightly loose on her. She is the tiniest adult cat - 2.5kg. I can't fit the bleeper tag on, so sewing it on is the only option really. I hate collars on cats as a rule, but she isn't fazed at all. She had a collar on when she was found as a 6 month old stray (over 2 years ago) which I binned on day one. Anyway, for now, a bell is better than nothing.