High Performance solar lights stays lit for up to 12 hours Lights up automatically every night / auto - off switch High output surface mount LED technology for brilliant white light 3x brighter than standard LEDs 2 long life AA Ni-MH rechargeable batteries included Durable powder coated Black aluminum Will fit over a nominal 4x4 wood post (actual dimension of opening: 3-5/8x3-5/8) Quick and easy Do It Yourself installation. 12 Lumens / 4500- 5500 Kelvins