★Single 9V battery can be used continuously for up to 30 hours, automatic shutdown function to save battery life ★Precise measurement & over-range measurement warning signs, there will be warning signs if the limit is exceeded ★Light weight, easy to carry, can be carried and measured anytime, anywhere ★Miniature condenser microphone sensor, accidental drop can also protect the sound head from normal use ★If you encounter problems during the purchase process, you can contact by email, and we will reply to you within 1-8 hours, Manufacturer: LLAWQSM