Early shock absorbing pole tip ferrules were notorious for breaking. After creating generations of spring loaded ferrules the latest is G5. The carbide tip is embedded securely in the plastic housing which is firmly attached to the ski pole; the independent damping system means that if it fails the skier can still ski home with an intact tip.  

This generation has a metal plunger and stiffer spring. The end of the bolt is made of a 5mm alumina ball - as hard as tungsten carbide and with a very low coefficient of friction. Because of the unpredictability of the fatigue life of the springs each pair of ferrules comes with two extra springs.

 These fit poles 9-11mm in diameter. Sold as a pair.