Professional Grooming comb with stainless steel rounded needle. This comb is specifically design for pet owners to groom their pets without worrying that it will hurt them. Most commercial combs have sharper needle which have slight risk that inexperience owner will hurt their pet. Having that in
It takes some practice to use them correctly. If you're not careful, you can rip a whole lot of fur out!
I just use a fine toothed metal comb for my chins, looks like this
Personally I don't advise using the professional chinchilla combs unless you know what you are doing. The one tunes linked don't look bad and are more rounder tipped then I've seen, but some are literally needles as comb teeth which can actually scratch up the chin if you aren't careful, so keep that in mind if looking at other professional ones.