In a word – no! We use the Avantis lock on our composite and uPVC doors while patio doors and French windows all feature the latest AV2 lock. Both are fitted with a revolutionary locking system known as Ultion. This dynamic mechanism ensures that your door can’t be opened by anyone other than yourself and your family. Even if a possible intruder manages to snap the lock twice, it still wouldn’t open. That’s how tough it is! And even if you leave the key in the lock while you’re at home, it wouldn’t make any difference when it came to an attempted break-in. The locking system would remain as effective as ever. In other words, Ultion is the best locking system you can find on the UK market today.