I really appreciate the product, the service with the free samples, the "no chains" option was well worth it as no more catching up in window handles! And more modern a look too. The sending though of a double hook for me enabled me to measure spot on. Being able to order by the slat, makes amazing good sense rather than send in the measurements of 6 windows and wait and see if the right number of slats comes to match all the hooks existing on the rails. With your approach I was able to order a spare 10 drops - just in case! Loads of praise from me. Promptly received so vey pleased.