Chuck Adapter for your oversized drill chuck, quickly converting it for precise drilling with micro size bits. Drop forged steel can hold 1mm 1/32" (0.79mm) inch as shown in picture or larger conventional drill bit. 1/4" (6.35mm) easy snap-in hex shank allows hex drive power tools to use conventional drill bits Easily locks onto and releases drill bits. Hold bits up to 1/4" (6.35mm). The 1/32" (0.79mm) inch drill bit in the picture is not included.