product overview:

1. **Product Name/Model Specification**:

The product name is direct ophthalmoscope, and the model specification is YZ11E.
2. **Scope of Application**:
Used for examining the fundus and refractive media.
3. **Product Performance or Features**:
It adopts a halogen - tungsten light source and has 6 types of diaphragms, 2 types of filters, and 24 compensation lenses (diopter compensation plates). The light beam of the halogen - tungsten light source passes through the condenser lens, diaphragm hole, projection lens, and is turned by the reflector and then emits parallel light rays that are projected onto the fundus of the examined person. After the doctor rotates the compensation lens control panel (diopter panel) to correct refractive errors, the fundus and refractive media of the examined eye can be observed and examined.
4. **Main Structural Composition**:
It consists of a head, a handle, and an adapter.
5. **Technical Characteristics**:
- Compensation Lenses (Diopter Compensation Plates, unit D): 0, ±1, ±2, ±3, ±4, ±5, ±6, ±8, ±10, +12, ±15, ±20, - 25, - 35.
- Diaphragms: slit, central grid, full diaphragm, medium diaphragm, small diaphragm, semi - circular diaphragm.
- Illumination Light Source: 3.5V 2.8W halogen - tungsten bulb.
- Power Adapter Input: 100 - 240V a.c. 50/60Hz.
- Power Adapter Output: 5V d.c. 1A MAX.
- Internal Battery: 3.7V d.c. 2600mAh Li - ion battery.
- Altitude: ≤3000m.

- Usage Environment: Usually used in an indoor darkroom environment.

detail picture: