Silca has been using this unique leather main seal since 1917. Since the 1960s, it has been produced in Milan's fashion district from residual material left over from the manufacture of handbags, car interiors and luggage. The leather gasket works smoother and more reliably than rubber O-rings, with unmatched resistance to heat and dirt! Ø 30 mm for aluminium pumps from 2008 onwards, Ø 28 mm for older steel pumps from 1917 to 2008. The leather seal is used to replace the main seal.