No. 2-S spiral ratchet reamer is self-feeding spiral design for extra-fast and easy hand reaming please note 2S reamer is not suitable for use with power tool. Nos. 2 and 3 ratchet reamers have long taper design that will not dig in suitable for use with power drives. No. 254 spiral ratchet reamer has hollow center for reduced weight for manual reaming only cannot be used with power drives