SUTTON TOOLS® 7/16"-Hex Quick-Change Extension Bits fit with 7/16"-Hex Shank Power Bits including Auger Bits, Self-Feed Bits, Holesaw Arbors etc.
They can also be used together for extra-long reach applications.
The recessed quick-change spring-loaded sleeve prevents accidental release.
Specifications

Shank - 7/16"-Hex - With Power Groove
Drive Size: 7/16"-Hex - Quick-Change
Length: 300 mm (12")