Extending Multi-Bit Driver Extend your reach, locks every inch, 3-Zone Comfort Grip. Users must complete jobs that require a variety of length drivers. The IRWIN Extending Multi-Bit Driver extends from 5" to 11", quick-locking mechanism securely locks at each 1" increment (7 lengths), so users can easily get into hard-to-reach spaces. In addition, the tip accepts insert and power bits for maximum versatility and ease of replacement.