SHAPE Border:  70 mm (B70) (H26) CORPO:  60 mm for  58 mm tamper RIDGE: RIDGE: RIDGE: Ridgeless SHAPE: Cylindrical with Convex Bottom The shape was created by I.M.S. to obtain the proper ratio between the base and height of the coffee puck in relation to capacity. The filter is cylindrical with a convex bottom to collect the coffee towards the center during percolation. This shape has been designed to exploit the whole coffee puck, which also facilitates drying and expulsion. Best combined with bottomless portafilter holders. PERFORATION I.M.S. perforation is exclusive and patented PERFORATED AREA: √ò 49 mm area optimized in relation to the shape of the filter. NUMBER OF HOLES: 715 HE spacing (E) The number and distribution of the perforations are designed to balance the delivery in relation to the height and shape of the filter and perforated area. HOLE DIAMETER: 0.30 mm SHAPE OF THE HOLE: CIRCULAR with CONICAL cross section. COMPETITION PERFORATION: Relaminated and Recalibrated. FINISHING TUMBLING: Wet vibrofinishing with ceramic inserts and drying with corncob PICKLING: Passivation and preparing of the material ELECTROPOLISHING: smooth surface with unmatched sanitary and non-contaminating qualities is obtained.