Actually helps to buckle effortless as handy. great simplicity. Namely, suppresses audible and visual warning unfastened ... because the system always detects a buckled belt! (Normal!). Perfect for my Seat Leon 2013 but could not install it in the 2004 Peugeot 307 for my son who nevertheless has the same loop size! I have yet measured with a calliper and the measures are the same: 21 mm wide and 3 mm thick. just be a problem notch the location itself ... compatibility with vehicles should be more detailed and explicit.