... , ECO, IIR, ACR.· Color: Regularly black, red, blue, yellow for rubber material, for silicone, any colors are available according to your panton ... of all kinds rubber material, please choose the suitable one for your items, thanks. Material NameHardnessWorking Temperature (Degrees)Standard materialNBR40~93 ... visit our factory in person at any time. rubber washer for auto parts