HUALINGKANG Ozone Generator. Purchased used. I bought it for my pet, but I only used it about twice. It makes a rattling sound, but it supplies oxygen properly. For those who understand that it is USED, and for those who need it for pet treatment, etc., please consider. Price negotiations are also welcome. - Brand: HUALINGKANG - Function: Anion function - Timer function: Yes I am also selling a cover to put your pet in.