I've had many different sets of Exacto knives since my early airplane modeling days.  The knives are what I expect Exacto  to be in terms of quality and safe use.  I purchased a nonExacto set from Sears and my first use the handle broke where the blade fits into the handle.  Luckily the blade missed my finger, but I tossed them and returned to Exacto.  These work and I feel comfortable using them.