The Wattstopper HBL1 is a high bay attached aisleway Fresnel lens providing 60 ft 20 ft coverage at 40 ft mounting height, engineered for linear aisleway detection patterns in commercial warehouse and industrial high bay applications. Designed to detect walking motion along aisles, it attaches directly to compatible Wattstopper HB-series power modules for a modular, mix-and-match installation. UL listed as part of the Wattstopper High Bay sensor system.