These precisely-machined tips are made of surgical stainless steel. The size is laser imprinted on each tip.
The size and length of a tip will determine the size of cable they work with:
US000, 00, 0, 1, and 1.5 tips have a MINI join for all lengths.
US2, 2.5, and 3 tips have a MINI join for 3" tips and a SMALL join for 4" and 5" tips.