​Bar caps are offered in three types of material:

• UHMW-PE – Standard material
• Nolu^® – SR​ – Is a speci​​al UHMP​WPE with modified molecular structure that helps guide PET containers in high speed applications.
• Nolu^® – S – Is a unique compound of UHMW and a solid lubricant.
  
  
  It drastically reduces the coefficient of friction, maintaining the
  characteristics of UHMW. Nolu-S has a better thermal conductivity compared with UHMW.

Each material has its own special characteristic and application consideration.