Product features: 15h standby, carry it with you, no consumables, sterilization and anti-allergy, remove PM2.5, purify smoke.How it works: Utilizes a carbon fiber brush system to release negative ions into the air. The released negative ions attach to air molecules and unclean particles in the air, making them negatively charged. Negatively charged particles repel each other, fly out of your breathing space, and are attracted to an approaching positively charged surface, forming large particles that sink to the ground by gravity, thus avoiding entering your respiratory system.The negative ion generator has no filter, environmental protection and no consumables, and does not need to be replaced for life.Body size: 79.7*18.8*12.7mm, applicable area: 1m, battery capacity: 250mAh, machine net weight: 20g. Rated power: 1W, main material: ABS, power supply mode: USB.