1. 300mm Extension Design: The extension rod length reaches 300mm, significantly increasing drilling depth and effectively solving the problem of insufficient drilling depth with Forstner bits. Suitable for various woodworking, furniture, and DIY deephole drilling scenarios. 2. Compatible with G3/8 Bits: Features a standard G3/8 hex shank design, compatible with various specifications of bits (Forstner bits/flatbottom bits). Adaptable to common electric drills, impact drills, and other tools on the market, easy to install and widely applicable. 3. Quality Carbon Steel: Made of strength carbon steel with wearresistant and corrosionresistant surface treatment. Offers toughness and impact resistance, resistant to deformation or breakage, ensuring longterm intensity use. 4. Includes Mounting Hardware and Hex Key: The set comes with a hex key and two fixing screws, securely fastening the bit to the extension rod to ensure stability and safety during drilling.