Klein Tools 5/16" Heavy Duty Nut Driver is a professional-grade tool designed for fastening nuts on threaded rods. With its hollow shaft, this nut driver allows for unlimited bolt length, making it ideal for a variety of applications. The color-coded handle provides easy identification of different sizes, while the wrench assist feature offers additional torque when needed. The magnetic tip helps retain nuts, ensuring a secure and efficient fastening process. The classic cushion grip handle provides comfort and control during use.