Orifice reducers, flexible poly that will turn a bottle opening of between 18mm and 20mm into a fine stream. The flexible fins allow some size flexibility. Package of 10 units. Larger quantities available by contact us.  We are a 21 year veteran EBAY seller of medical bottles and accessories. Factory fresh, never used.  Also available in different listing are 15mm and 22-24mm orifice reducers. Flat $5.95 shipping for any quantity to all US points.