All are our standard 1'''' (2.5cm) long, A 1/4'''' (6.3mm) hex shank bits. Phillips bits are NOT anti-cam. Square socket screws are in RV's, cabinets, other places. 1/8'''' square fits newer Remington butt plates. Mfg: Brownells SPECS: Allen Bit Set includes all ten "185" series bits listed in our MAGNA-TIP(R) chart. Phillips Bit Set includes #0, #1 and #2 Phillips Bits. Square Bit Set includes 1/16'''', 3/32'''', 1/8'''' and 9/64'''' Square Bits. "Other Bit" Master Kit includes the Allen, Phillips and Square Bit