Two Component Tin Catalyzed RTV (Condensation Cure) Liquid Silicone Rubber — HN-620 A/B HN-620 A/B is a two-component, tin-catalyzed RTV2 condensation cure liquid silicone rubber specially developed for flexible, high-precision mold production. Activated by a tin catalyst and mixed at 100:2–3, it vulcanizes at room temperature and delivers ultra-fine pattern replication with remarkable tear resistance for high-volume, repeatable mass production mold making . Tin Cure vs