- Keep people awareness of momentary lapses caused by sleepiness and tiredness<br />- With on/off switch<br />- Powered by 4*AG3 batteries (included)<br /><br />                                                                                                                                Dimensions: 2.76 in x 1.57 in x 0.55 in (7.0 cm x 4.0 cm x 1.4 cm)<br />Weight: 0.46 oz (13 g)<br /><br />