Werner trade double 20 tread extension ladderthis extension ladder from werner comes with slip resistant feet for added stability whilst working its light 108kg aluminium and plastic construction is extremely durable as it can hold up to 150kg it extends from its storage height of 297m to a maximum height of 491m the d shape slip resistant rungs have been designed for additional safety and comfort making it perfect for accessing higher harder to reach areas of the home such as 1st flo