Overcharging circuit protectionDeep discharge protectionNO RF noiseNo blackening of tube endsTube: 9 11 18 watts (optional)Battery: 6V, 4.5 AH; Field Maintenance Free (FMF VRLA)"Duration : 4 hrs. with high brightness 6 hrs. with lower lumenPacking : 3 ply cardboard. We can also provide customised design, based on the application requirements