| PARAMETER | SPECIFICATION |
| Illumination | Large light spot (3.2mm), small light spot(1.6mm),Slit Central-net,Red-free filter |
| Diopter compensation | 0、±1D、±2D、±3D、±4D、±5D、±6D、±8D、±10D、±12D、±15D、±20D、-25D |
| Light source | 2.6V、2W Mini-halogen lamp |
| Power supply | 2*1.5 V dry cell (2#) |
| Input power | 5VA |
