The irwin pro screwdriver bit set 31 piece contains a mix of popular screwdriver bits the bits are manufactured from high grade s2 steel and are engineered for use in hand drive or power tool applicaions supplied in a handy carry case comes with 7 x 25mm phillips bits ph11 ph25 ph31 2 x 25mm tin coated phillips bits ph22 7 x 25mm pozidriv bits pz1 pz25 pz3 2 x 25mm tin coated pozi bits pz22 3 x 25mm slotted bits 6 8 8 10 10 12 4 x 50mm phillips bits ph24 2 x 50mm pozidriv bits pz22 3 x 50m