Pure Crystal dog multi-filters, made by GEX, with 2 filters per pack, usable for approximately 2 months. Total: 4 filters - Brand: GEX - Product Name: Multi-Filter - Quantity: 2 filters per box, two boxes total - Compatible Models: Dental Water - Usage Period: Approximately 2 months - Material: Pure Crystal Thank you for viewing. I received these as a gift, but I won't be able to use them all, so I'm offering them to someone who needs them. Shipping costs will be high due to the size of the boxes, so I am unable to offer a discount.