Dab tsi yog qhov siab ntawm lub teeb taws teeb txhais tau?
Kho headlamp qhov siab txhais tau tias qhov siab headlamp tau hloov kho kom tau txais qhov zoo tshaj plaws irradiation deb thiab zam kev phom sij. Nov yog kev teeb tsa kev nyab xeeb. Feem ntau, lub cev muaj zog siv los kho qhov siab ntawm headlamp electrically, thiaj li tau txais qhov zoo tshaj plaws irradiation deb thiab zam kev phom sij thaum tsav tsheb.