Set of cylindrical inserts designed to adapt bottle holders and bottle carriers to different container sizes, such as 12-ounce bottles, 25 cl, 30 cl, 33 cl, 37.5 cl, and 44 cl cans. Each insert is a ring or shell that fits into the bottle holder's slot to reduce the internal diameter and keep the container centered and stable. The collection includes versions with or without identifying text, slim variants, and a flat closing lid. A diameter test tool allows you to check the correct size before use. The tallest insert measures approximately 8.1 cm