The product is a NOS Black & Decker 1/4" Hex-Key Chuck & Key Set with a threaded shank, specifically designed for use with no U-1500 Jacobs chuck. The chuck features a keyed design and a 1/4 inch mounting size, making it compatible with a variety of drilling applications in the CNC, metalworking, and manufacturing industries. This high-quality chuck and key set from Jacobs offers reliable toolholding for precise and efficient drilling operations.