Tri Tie Micro PulleyIdeal For Arborist Rigging Where Three Independent Tie Ins Are Required. One Orange, One Black Anodized Aluminum Sideplates, 1 1 4" Aluminum Sheave, Bronze Bushing, And Aluminum Axle. The New Cmi Tri Tie Pulley Is Built To Work. The Anodized Side Plates Are Made Of 7075 T6 Aluminum. 7000 Series Alloys Are Some Of The Highest Rated Strength Alloys Available Today And Are Used In High Performance Applications Such As Aircraft, Aerospace, And Competitive