The gutter caterpillars are ineinanderleigend save space packed in a carton. After cleaning the gutter, the installation is very simple - just insert or gently arrival / impressions. The parts are designed to prevent even climbing over by eg martens; But is not the problem with us. Will report again after the winter on the effectiveness of cleaning or rather "the dirt defense". As far as full marks!
June 2015: The Gutter caterpillars have very well kept leaves from the gutters! I'm curious about the life of ... more later!