Streamlight Polytac XPOLYTAC X INCLUDES TWO CR123A LITHIUM BATTERIES CLAM BLACK, 88600 Multi fuel Uses 18650 battery pack or two CR123A lithium batteries TEN TAP Programming allows the choice of three programs: 1) high strobe low 2) high only 3) low medium high High: 600 lumens; 205m beam; runs 2. 75 hours (CR123A); runs 3. 5 hours (18650 battery pack) Medium: 260 lumens; 135m beam; runs 5. 5 hours (CR123A); runs 5. 75 hours (18650 battery pack) Low: 35 lumens; 50m beam;