Efficient filtration: Monotub adhesive filter disks provide effective air circulation while filtering out contaminants, supporting a healthy mushroom cultivation process. Excellent performance: These filter discs allow moderate fresh air exchange, maintaining a clean and controlled environment for mushroom growth and plant cloning, while preserving optimal humidity levels. Perfect size: Each filter pad has a diameter of approximately 2.95 inches, with an adhesive border of about 0.2 inches, designed to fit monotub air holes up to 2.5 inches in diameter. They effectively cover and protect ventilation points. Easy to install: Simply peel off the backing and apply the filters directly over the holes. The adhesive design allows for quick installation and removal, making maintenance convenient. Filter set included: This package contains 24 pieces of 2mm thick mushroom filter pads, suitable for use with monotubs, fruiting chambers, and other cultivation setups, providing ample supply for regular use and replacement. Color: White Material: Cotton Thickness: 2mm Package Contents: 24 x Monotub Adhesive Filter Disks Note: Light reflection and display settings may cause slight variations in color between the image and the actual item. Measurement tolerances are within +/- 1-3cm.