Gurtwickler does what he should

We bought 3 Gurtwickler for our large patio windows about 2 months ago.
The installation is very easy (roller shutter belt threading into the unit and hang it on the plastic nose, then wrap again - ready!). The devices go far reliably our shutters at the set times up and down.

A small drawback is that the built-in timers are out of sync. Although they are precisely adjusted to the same second, the time varies between the individual winders for about 1 week to 30 - 60 seconds, so do not go all the shutters at exactly the same time. But we can live with ...