This fits into the group handle 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 a backflush disc. Spoon approximately 0.5 teaspoons of backflush cleaner into the basket. Reinsert the portafilter into the brew group and turn on the pump. In 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 cleaner is blown up into the brew group, 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 handle and rinse the cleaner out of the handle. Reinsert the handle into the machine again and do a couple more backflushes without cleaner, using only water. Finally, remove the handle and turn the pump on and off a few times to flush out the remaining cleaner from the brew group. Color: Silver Material: stainless steel Size: Length: 70 mm. Bottom diameter: 58 mm Diameter: 60 mm. Height: 20 mm. Package Contents: 1 * Blind cup, non-porous filter holder 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.