Antal Tulip Organisers come in groups of 2-6 sheaves with a range of 2 diameters. The 45mm sheave is made from a high resistance resin with a ‘self captive’ double side ball bearing. The 60mm sheave is made from a Teflon coated aluminium which can handle very high loads. The sheave also has an axial bearing made from composite fibre with large round bearings ‘self captive’.