The diameter of our replacement solar light is 8.1cm on the top and the base diameter is 6.8cm. Please check your solar light's size compatibility in advance. It takes 6-8 hours to charge, then it can work for 8 hours at night. Please turn on the switch on the top before charging with sunshine or good daylight. It contains Ni-MH-AA battery with 600mAh/1.2V, and the solar panel polysilicon efficiency is 25%. The LED chip is located on the underside of the solar replacement top and provides a soft warm light in the dark, 7 lumens. The solar light tops are very suitable as replacement solar sprinkler lights and also for most solar lights, solar lamp replacement fixtures. Please place the round solar panels in direct sunlight for best performance. But remember, do not place it in a place full of artificial light (the light sensor is too sensitive and will turn off the solar light).