The fabric will resist the long-term effects of exposure to chlorine giving it fantastic durability, while the flatlock seams eliminate chafing and skin irritation. The back pocket is big enough to store energy gels or an MP3 player, with a hole for headphone wires to be routed through the inside. The material of the top also blocks harmful UV rays with a protection factor of 50 – so you needn’t worry about them getting sunburnt in the summer heat.