Replacement Sleeves for older twist-to-lock poles to prevent dirt and debris from entering the shafts. In most cases, if your poles go up to 140 or 145cm you will need the 18 mm sleeves for the upper shaft and 16 mm sleeves for the middle shaft. if your poles go up to 130 or 135 cm you will need 16 mm sleeves for the upper shaft and 14 mm sleeves for the middle shaft. If you need help finding the right size please contact customer service. Sold as a pair.