Key size requirements: the inner post has a diameter of 4 mm, make sure your keyhole has a diameter of more than 4 mm, it does not matter if it is larger. The height of the standard inner column is approx. 12 mm (offers space for 2-12 keys), if there are special keys, please measure beforehand High-quality materials: key clip made of metal is made from anodised (and therefore extremely scratch-resistant) aluminium used in the aircraft industry, as well as high-quality stainless steel. Very pleasant to the touch thanks to the hand-cut round edges. Easy to carry: holds your existing keys (so you don't have to go to the locksmith) and you can attach your larger car keys or remote door opener with included snap ring. Save space: Forget bulky key rings, uncomfortable stitches from keys in your pocket and key clips forever - organise the mess and free your bags with the compact key holder Beautiful gift: pendant organiser is the perfect little Christmas gift or gift for any occasion that all key carriers will love