Premounted Skis - come with the bindings already installed on the skis that are ready to go as soon as you receive them. Just click your boots in and enjoy.
Flat Cross Country Skis - are skis that do not have a binding that is included. A binding that matches your boot type much be purchased separately, and then mounted on the skis.
NIS Cross Country Skis - have a plate that is already attached to the ski that requires an NIS NNN binding that slides onto the plate. In most cases a NIS NNN binding must be purchased separately.
Bindings Included - means that there is a specific binding that is included with the ski, that is not already installed on the ski. In most cases this is an NIS NNN Binding.
Flat (NNN BC) - means that the recommended binding for this ski is an NNN BC binding that is sold separately. NNN BC bindings have a wider platform and stronger toe bar for breaking trail in ungroomed snow, and extra stability.