With automatic voltage booster, which can change the voltage of two AAA batteries from 3V to 4.5V and give enough light.
The efficiency of LED lamp is over 10 times of ordinary peanut bulb, so it has the functions of environmental protection and energy saving.
The multiples of lens have four selections: 1.2X, 1.8X, 2.5X and 3.5X
The multiple is shown on the right upper corner of lens.
Select a suitable multiple in accordance with the distance to an object.
The suitable multiples in accordance with the distances to objects are shown in the following: - 1.2X: 520 ~ 620 mm - 1.8X: 230 ~ 320 mm - 2.5X: 150 ~ 250 mm - 3.5X: 80 ~ 120 mm
Head-band adjustment: - First to press the buckle marked " open " on the band, then you may release the band and adjust required head size. - If you want it tight, just pull the end with hole outside. - After tightening, just fix it by pressing the buckle aiming at the hole on band. - There is no standard to say tight or loose. It depends on the user's feeling by comfortable principle.