Black Diamond's Trekking Pole Tip Protectors stop that annoying 'chip chip' sound on rocks and roads as well as preventing scratching to the rocks.
Black Diamond says:
Ideal for hard surfaces or rocky trails, the quiet, non-marking Black Diamond Rubber Tech Tips avoid rock and trail scarring, and offer excellent grip and durability. Works as replacement tip for our Spring 2012 and later only trekking poles and all model Z-poles. Does not work with First Strike, Trail Back, Syncline poles. Sold in pairs