It would be good to have a breeder show you how to do a hair ring check since you have males. I always show my customers how to do a hair ring check who purchase males, just to play if safe and so they are prepared, just in case. I always check any male, baby or adult, before they leave. I did lose a male chinchilla who had just a single hair wrapped around the base of his penis. It can cut off the circulation and be very serious. I am not trying to scare you, but it is important. I check all of my males once a week and am also always on the look out for a male who is cleaning himself more than usual or "hanging out" of the sheath. I have 2 males that always have large hair rings; one guy has them daily. (He is the one I use for hair ring demonstrations). Most of the time, in my herd, only a few males that are in breeding will have them (maybe 4 out of 100 males), but I have had a baby male as young as 3 months get a hair ring. This may be caused from the baby male riding the other baby males in the cage, to establish dominance. If you have only 1 chinchilla it will probably not be an issue, but it would still be good to know how to check, just to be safe.