TheSP Air Sealed Flat Head Mini Ratchet is available in two sizes: 1/4" (No. The 1/4" drive has a bolt capacity of 5/16" Each light-weight ratchet uses only 2.5 cfm and features a reverse lever that can be operated with one hand, an air regulator and a 360-degree exhaust sleeve so the exhaust can be pointed away from the technician. ).