Mast section - 2 ring. This is the second section up. The 4.5m sail uses two of these sections, the 5.5m sail uses 3. It has 2 rings painted on it for easy identification during assembly. Please note; if you have 3.5m sail and you're getting a 5.5m, you'll need to buy an extra one of these sections - you only get one included with the sail.