... (different grade),metal,brass ,copper3.surface treatment for prototypes painting,anodizing,electroplating,brushed,sandblasting,printing,transpartent, ... case, Digital Ultrasonic Diagnostic Imaging case, CT, cosmetology handle, Multi-frequency Transducers ♦ Automotives , car lamp/light, car dashboard, car ... the size and material of the products .For products with special surface treatment,like painting ...