Schaefer Marine 3 Flat Base/Alum Cheek/Delrin Sheave Series. The Schaefer Marine Lift Cam features a high working load capacity and ensures smooth operation. There are two Delrin bearings in the sheave which ensures smooth operation and high safe working load. The lower base is made of stainless steel and distributes loads to a larger surface area to ensure the highest possible safe working load. There is a Delrin plain bearing sheave which ensures smooth operation and a safe working load. Specifications for Schaefer Marine Series 3 Flat Base/Alum Cheek/Delrin Sheave: Manufacturer: Schaefer Marine Color: Black Package Contents: Schaefer Marine Series 3 Flat Base/Alum Cheek/Delrin Sheave Schaefer Marine 303-09: 3 Flat Base/Alum Cheek/Delrin Sheave Series