... (different grade),metal,brass ,copper3.surface treatment for prototypes painting,anodizing,electroplating,brushed,sandblasting,printing,transpartent,rubber ... 4. Products application ♦ Medical devices, like B-Ultrasound scanner case, Digital Ultrasonic Diagnostic Imaging case, CT, cosmetology handle ... the size and material of the products .For products with special surface treatment,like painting,silk ...