Collet Set ER20 Face Shape Round Max Size 0.3810 in Overall Length 1.2400 in Collet Type ER20 Head Dia 0.8300 in Compatible with Product Type BR Standard Collet Chucks DIN 6499 Collet Pockets DR Standard Collet Chucks ER Standard Collet Chucks ESX Standard Collet Chucks RD Standard Collet Chucks