This is the filter that came with the purchase of the Aair 4 Plus. There are no smokers or pets in the household. Immediate purchase is OK. 【High-Performance Filter】 The H13 HEPA filter removes 99.95% of fine particles and allergens, improving indoor air quality. 【Appropriate Size】 The product size is 150mm and fits various air purifiers. It is ideal as a replacement filter. 【Expiration Date】 It has an expiration date of approximately 6 months, and regular replacement allows you to always maintain clean air. - Filter Type: H13 HEPA filter - Product Size: 150mm - Product Class: H13