EOC and SYOZ Collets DIN 6388 Standards Collets
This collets are EOC collets. The EOC Collet system has also been called "SYOZ" collet by some manufacturers. So also call OZ collets. They look like ER or SK collets, but the dimensions are different.
ER, TG, SK, SC, and SYOZ collets all have unique length and diameter measurements. The best way to tell what type of collet you is to measure the length of the collet.
RICO CNC is the best source for all types of CNC and router tools needs like these SYOZ/EOC Collets, ER collets, SC collets, SK collets. Also can supply a line of CNC collet chuck systems, shuc as ISO30 tool holders, HSK63F tool holders, BT30 BT40 tool holders, and cnc spare parts and accessories.