My snap locks do not come with a safety key, only a regular metal key. Maybe thats what they meant???? You can not really use those metal keys intraorally unless you really trust a parent wont drop it into the back of there childs throat which they will, people have tied dental floss on them to prevent choking but there still very hard to use. a Safety Key is a long handled key about the size of a pencil.
BTW all orthodontists should have there own, I give ones to general dentists but if an orthodontist asks me for them I tell them where to order, THEY should have them on hand should a patient lose theres