A dedicated set for the Ultion range of cylinders, working on the U series cylinders and up to the latest version of the WXM. The U series key has cuts for the dimples on one side of the key and a special track cut on the reverse to deal with the passive pins. The WXM key is cut on both sides and fits in all profiles of the WXM cylinder including the newest alps version. We advise using rubbers to protect and prolong the tip of the key as the WXM as hardened key pins which require the severe ramp on the tip of the key to be intact.. This Ultion bump key set is very tough and durable.