This unit's housing is constructed of GRP, a material that has been used for years in the marine and aviation industries. Using this material enabled Hartl to create new forms and shapes while maintaining strength. It's light weight allowed for larger housing sections to be utilised. All major service points are now very easily accessed - a flywheel replacement, for example, is now possible without housing disassembly. For small on-site damages, the damaged section can easily be removed and repaired insite using the emergency repair kit.