... , environmental safe material, non-toxic, smooth feel, excellent transmission. The hardness of silicone rubber can be graded between 30 to 80 shore ... ) Hard plastic keys. 7) Soft, smooth, flexible, stain-free and water-resistant in one whole piece complete seal style.8) Applications ... and mobile phones. 9) Soft, smooth, flexible, stain-free and water-resistant in one whole piece complete seal style