The inner diameter of the non-pressurized porous filter basket is 51mm, which is generally applicable to 51mm bottomless portafilters. BUT some original standard 51mm portafilters may not be deep enough to insert the filter basket. It is highly recommended that you carefully measure the inner diameter and depth of your portafilter before purchasing. The product includes 3 filter baskets and a blind filter. The depth of the 4-cup filter basket is 36mm, the depth of the 2-cup is 25mm, the depth of the 1-cup is 19mm, and the depth of the Backflush Blind Filter is 14mm. The product is made of stainless steel and is safe. It is very easy to clean and convenient to use next time. The product is slightly magnetic, which allows it to be connected to a magnetic dosing funnel. Please read the product information carefully before purchasing, thank you! Color: silver Material: stainless steel Package Contents: 1 x Single Cup 1 x Double Cup 1 x 4-Cup 1 x Blind Cup 2 x Brush Only the above package contents, 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.