There are 4 types of backcountry cross-country ski bindings on the market, for different uses.
1- The NNN binding system: this system is used in classic cross-country skiing, but it is also often used in backcountry skiing for short outings and for its compatibility with lighter and faster boots.
2- The NNN BC binding system: these bindings are widely used in backcountry cross-country skiing, especially in the Laurentians region and for polar expeditions. It is a good compromise between gliding and pushing without sacrificing control on descents. This binding system is similar to the NNN system, but it is equipped with a more robust and wider metal rod.
3- The 3-Pin (75 mm) binding system: this is one of the oldest systems used in cross-country skiing. However, it is not compatible with mechanically groomed trails. On the other hand, it has the advantage of offering enhanced control on descents. Some 3-Pin models are lighter for cross-country ski touring, and other models are more robust and only intended for telemark skiing.
4- The Xplore binding system: this binding system is the most recent, dating back to 2022. These bindings position themselves between the 3-Pin system and the NNN BC system. They are as efficient on descents as the 3-Pin system, and as efficient on ascents as the NNN BC system. However, they are wider than the NNN BC bindings. Several cross-country skiers use Xplore bindings to replace their 3-Pin bindings.