... 3) Prompt delivery 4) Professional service Features of our flexible rubber bellows;· Working temperature: -100 to +300 degrees;· Hardness: ... Strength, Wear and tear resistance, Durable;· UL & SGS certification;· Rubber Material: NBR, HNBR, XNBR, EPDM, CR, NR, SBR, VMQ, ... ACR.· Color: Regularly black, red, blue, yellow for rubber material, for silicone, any colors are available according to your panton ...