These add-ons for Blum drawer boxes worked great for me. Installation was not difficult. If your cabinets were predrilled for mounting holes on the sides, then those holes are perfectly spaced for the mechanism that needs to be mounted to the cabinet. Just one extra hole must be drilled for the rear of that mechanism. Unfortunately, our Blum drawers did not have a similarly well-positioned hole already at the bottom of the box, ready to accept the little clip that is part of the kit, otherwise the installation could have been borderline easy. I don't know if other Blum boxes might have such a hole. If so, it would relieve you from needing to measure (or fashioning a jig) and having to drill a small hole through the metal part of the box, but even that isn't so much a bother. Once installed, the mechanism is nearly invisible and works fantastically well. The closing action is smooth and quiet. My wife is so happy not to have to hear the drawers slamming anymore. My o...