Product material: CR-V (chrome vanadium steel) Product size: length 65mm, opposite hexagonal hole size 13mm. This nut driver is designed to quickly and efficiently tighten or loosen nuts, bolts, hooks when installing roller shutters/panels or other projects and save you a lot of time and get the job done faster. Just put it in an electric screwdriver and install the nut or flap, no need to worry about spraining your thumb with other tools, reducing wear and tear on your fingers. Compatibility: The 1/4" hex handle is compatible with electric drills, saving time and effort. Application: Good helper for installing hurricane shade/panel Christmas lights, string lights, etc. Quick release wing nut and hook. Scope of supply: two pieces