Satco's 10-watt left-hand threaded bulb is an elegant and versatile lighting solution for commercial applications. The brass, left-hand threaded base helps to distinguish from the more commonly used right-hand threaded lamps. The use of a left-hand threaded lamp can be a theft deterrent, since the bulb will not fit in a right-hand thread socket. This bulb delivers 15,000 hours of cool white light. Sold as a 24-Pack