Features: Food grade material, non-toxic- and harmless, no peculiar smell, safe to use Environmental friendly, washable and reusable Use silicone which are safe material, no injury to the chest 15,17，19 ，21mm inserts to use with 24mm detachable 24mm inserts to use with 27 mm detachable shield; Insert to use with Breast Pump 24 or 27mm detachable shield. It will reduce the nipple tunnels down to 15/17/19/21. Almost for Brands with flange size of 24-27mm To reduce the existing funnels to smaller size; Is the best choice for new mothers 5 Specifications: Material: Silicone Optional Size : app.17/19/21mm Color: Transparent Quantity: 1 Pc Package Includes: 1pc x Flange Inserts note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!