Many reptiles ,such as lizard and turtle , all need the natural sunshine to live and grow. The UV rays included in sunshine will help reptiles to composite calcium so as to avoid the disease of Rickets, but when we breed them in our house , it is not easy to get the sunshine often and sometimes the high temperature from sunshine is also harmful to reptiles, so the UV mercury lamp would be the best solution for your reptiles . moreover ,this lamp is also used wide in the place where is short of the natural sunshine .such as coal mine.