USAG Protwist "Shock Series" Slotted Screwdriver-4x100mm (324 HPH)- for use with a hammer to free up rusted & frozen fasteners. Ultimate Garage stocks the popular slotted and phillips sizes in this series. See catalog photos for specs and details. These are identical to the Facom versions and come with a US warranty. The 4mm slotted shock screwdriver is the only one in the 14pc series that does not come with a hex bolster. Excessive torque via the bolster would damage the small slotted screws.