Lightweight High Intensity Lights. Acceptable Device for NCHRP-350. Operates on D-Cell Batteries. Tested to MUTCD and I.T.E. standards by an approved certified laboratory. Polycarbonate lenses and High Impact Polypropylene housing. Model 212-3LW is a 3 volt system that can operate on two to four D-Cell batteries, Type B Light. Continuous blinking operation day & night. Visible day and night. It will project adequate signal for over 60 days on two D-Cell alkaline batteries, and over 120 days with four D-Cell alkaline batteries. Batteries not included.