DescriptionModel Number : Breast Pump Horn Caliber Size Converter in a SetMaterial Feature : Latex Free,Nitrosamine Free,Phthalate Free,BPA Free,PVC FreeMaterial : SiliconType : Breast Pump AccessoriesAge Range : MaternityFeaturesbrand new and high qualityA set of four, multi size options, suitable for different lactating mothers.Suitable for most breast pumps on the market.Baby liquid silica gel is used. The material is safe and non-toxic. Please rest assured.The 17 / 19 / 21 mm caliber is applicable to the original 24mm horn, and the 24mm caliber is applicable to the original 27mm horn.Material:Infant Liquid SiliconeInner Diameter:17/19/21/24mm(0.66/0.74/0.82/0.94inches)This product is a personal product. Once it is disassembled, it cannot be returned or replaced. Please measure the size and take photos again.Package Includes:4 Pieces Breast Pump Horn Caliber Size Converter in a Set