Luminara is the most recognizable brand of flameless candles because it is the best!  I set mine to light at 6:00 p.m and have 5 hours of continuous light.  After 5 hours they go off automatically.  Then back on the next night at 6:00.  Runs on "C" batteries and they tend to last 4-5 months or a "Holiday Season!"   Size is 3"L x 3"W x 8.5"H.