Perfect Compatibility for Filter- Our ammonia reducer filer pads are very suitable for Quietflow LED PRO aquarium power filter 20 and 75 on the market. And the dimension of our filter pads is 3.74 x 0.7 x 0.7 inches. You can replace approximately every 2 to 3 weeks. Strong Purification Effect- Excessive ammonia nitrogen affect the growth and development of fish and cause water to stink. Our ammonia reduction pad remove excess harmful or toxi c ammonia and nitrogen while trapping excess waste, food and other organic debri. Pre-cut for Easy Installation- The filter pads are pre-cut for quick replacement. Use this ammonia reducer minipad in addition to the can keep your water clean and healthy. Long term replacement of ammonia filters - To maintain the ammonia nitrogen content in the fish tank within limits, it is necessary to regularly replace the filter pads. According to the test, the mini filter pad withstand too much sundries for no more than 4 weeks. [Kindly tip: For performance, rinse before putting in for Quietflow LED PRO 10 filter.] Color: As Shown Material: Sponge Package Contents: 18 x Count Ammonia Reducer Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.