Silit Sicomatic t-plus working valve. Suitable for all pressure cookers in the Sicomatic t-plus/classic series - item number: 2150257462. Material: High-quality plastic. Cooking with products from the Silit brand is a pure passion for enjoyment and unadulterated natural flavours. With the Silargan functional ceramic, the cooking experts from Riedlingen have succeeded in revolutionising cooking. Products from Silit combine form, functionality and aesthetics to form a harmonious whole. The Silit brand is part of the WMF Group based in Geislingen an der Steige and has been producing cookware since 1920.