The HTS4-10PK 10PC Bit Pack for #4 Hi-Torque® Recess features Hi-Torque® bits that typically fit 10-32 size Hi-Torque® recess fasteners including first and second oversize, plus 1/4-28 reduced head style fasteners. The Hi-Torque® recess was designed to provide very high installation and removal torques, very shallow recess for use on 120 and 130 flush fasteners in thin skins, and to reduce the need for end-load of the driver by the operator while installing and removing screws.