Reusable - The cotton coffee filters replace conventional disposable filters. They are permanent filters that can be easily emptied and rinsed after brewing coffee. Suitable for pour-over and coffee machines - The reusable coffee filters can be used just like regular paper filters. Plastic-free packaging - The reusable coffee filters are packaged without plastic in paper. Easy to clean – The filters are easy to clean. After each use, they should be rinsed with warm water and soaked in boiling water for 10 minutes every 14 days. This set includes 4 reusable filter bags made of 100% cotton in size 4 (dimensions: 12 cm side length x 19 cm width). The size is ideal as a replacement for standard paper filters in size 4 or for Melitta 1X4.