... 500, RTOP-800/1000Characteristics:1. Aluminum alloy frame, delicate appearance, user-friendly. 2. Automatic microcomputer control; touch key, 3. ... helpful for plants growth and improve the disease resistance 7. Has power failure memory, power failure time automatic ... difference ModelVolumeSize(mm)Period control modeIlluminance(LUX) Day period and night period, automatic 1-30 periods automatic.0- ...