With this CRL Glass Drilling Base, field glass drilling nightmares are a thing of the past. Ever show up to a mirror install just to find out that someone forgot to account for the power outlet? Simply attach your handheld, cordless or electric, drill to the mounted chuck, install the desired bit, add coolant and you are ready to cleanly field-fabricate the mirror. The adjustable stop and spring resistance of this base ensures safe and smooth drilling with minimal "blow-out". The base gasket secures the base from slipping while effectively keeping coolant corralled, reducing clean-up time. The base is available with either a keyless (GDB1) or Belgium thread chuck (GDB2). The lightweight design, durability and functionality of this tool makes it a perfect addition to any mobile installation operation.