This backflush disc fits into your portafilter instead of the regular filter. Backflushing your coffee machine helps remove coffee residue that builds up inside the group head. The blind filter can be used with cleaning tablets. Ensure your coffee machine has a suitable pressure relief valve and that the diameter is correct for your machine. HOW TO USE IT? Remove the filter basket from the portafilter and insert the backflush disc. Spoon approximately 0.5 teaspoons of backflush cleaning agent into the basket. Reinsert the portafilter into the group head and turn on the pump. After about 20 seconds, the pump will become very quiet. This is a result of the pressure now building up. Once the pressure has built up (quiet), turn off the pump. You will then hear a sound as the cleaning agent is flushed up into the group head, through the three-way valve, and empties into the drip tray. Repeat this process until the foam coming out into the drip tray is clean. Remove the portafilter and rinse the cleaning agent out of the portafilter. Reinsert the portafilter into the machine and do a couple more backflushes without cleaning agent, using only water. Finally, remove the portafilter and turn the pump on and off a few times to flush out any remaining cleaning agent from the group head. Color: Silver Material: Stainless Steel Size: Length: 70 mm Bottom Diameter: 58 mm Diameter: 60 mm Height: 20 mm Package Contents: 1 * Blind Disc, Non-porous Filter Basket Note: Ensure your coffee machine has a suitable pressure relief valve and that the diameter is correct for your machine. Only the above package content, other products are not included. Note: Light shooting 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 +/- 1-3 cm.