Illumination bulb

2.6V/2W mini halogen bulb

Big facula Φ3.2m, small facula Φ1.6m, slit light, central grid, no red

Refraction compensation: 0, ±1D, ±2D, ±3D, ±4D, ±5D, ±6D, ±8D, ±10D, ±12D, ±16D, ±20D, ±25D

Power supply

Two pieces 1.5v battery