This is a set of 5 baby bottles: a glass Pigeon bottle and plastic COMBI bottles. It also includes a Raku-Raku Milk adapter and Pigeon nipples that fit it. The glass bottle is a slim type, so it won't fit the adapter. The COMBI bottles will fit. Although it's not recommended, I haven't had any leaks using this setup. The bottles have been thoroughly washed and sterilized, but please understand that these are used items before considering a purchase.