Manufactured from 316l stainless steel with electropolish finish. Ra 32 finish or better inside and out. Ideal use for cell culture and reduces shear in delicate cell culture. Blade dimension: 5 3/4 x 2? Shaft oal: 14 1/2? Constructed of 316l electropolished stainless steel Marine impeller includes 1/2? shaft and impeller blade Omni and z-z paddles are one piece welded, 1/4? shaft