Outsunny Solar Powered LED Fence Post Cap Light - White Solar powered grid absorbs energy during the day and lights up during the night Automatically lights up during the night 2 rechargeable 600 mAh AAA Ni-Mh batteries Works perfectly on top of fence posts or other outdoor yard decor Overall size: 4.1"L x 4.1"W x 2.4"H; fits pole size 2.5" x 2.5"