The Zhoushan Island Overhead Powerline Tie is a 220 kV three phase AC interconnection of the power grid of Zhoushan Island with that of the Chinese mainland. It runs over several islands and consist of several long distance spans, the longest with a length of 2.7 kilometres (1.7 mi) south of Damao Island. This span uses two 370 metres (1,214 ft) tall pylons, which are the tallest electricity pylons in the world. The north tower on Damao Island (大猫岛) was completed in 2009, and the south tower on Liangmao Island (凉帽岛) was completed in 2010. These pylons resemble those of the Messina Strait, but are steel tube lattice structures.