... with less coefficient of friction, high limiting speed, large size range and various structure.2.Features : Shield / closure: open ball ... Z and ZZ (2Z).With a snap ring groove in outer ring N.With a snap ring groove in outer ring ... machinery , Motorcycle , Motor , Pump ,Fan,Air conditioner ,Microwave Oven,Range hood,Sewing machine,Massage Chairs,Textile machinery, Electric tools,Agriculture machinery ...