... 5%-95%5. Precision : ±0.1%6. 4 Pre-set : 5%, 16.25%, 72.5%, 95%BUTTON INSTRUCTION1. Select Button: When ... , press ↑ ↓button to choose 4 kinds of pre-set : 5%, 16.25%, 72.5%, 95%2. RED4 POWER: The ... programme. Before left factory, all the data have pre-set well, don't change it by any way, and ... lamp light, and press arrow ↑ ↓ to choose pre-set rank, and press select button again, indicator lamp power-off ...