Silicone Rubber Bouncing Ball 30mm for Vibratory Sifters YUNZORI | Direct factory price | OEM & ODM supported | ISO 9001:2015, FDA 21 CFR 177.2600, LFGB, RoHS, REACH Product Overview Silicone Rubber Bouncing Ball 30mm for Vibratory Sifters is engineered and moulded in-house by Dongguan Yunze Silicone Products Co., Ltd. Manufactured from 100% platinum-cured silicone rubber (45°A Shore A, -40°C to +250°C / -40°F to +482°F), this silicone vibrating screen ball is designed for