More Info in Amazon.co.uk : http://www.amazon.co.uk/gp/product/B00591R486?tag=elgatoandal06-21

2XU Men's PWX Short Sleeve Compression Baselayer - White Medium

Using PWX FLEX for optimal flexibility movement
High power denier to support triceps biceps pectorals deltoids
Reduced muscle fatigue damage
Core body support
Raglan sleeve construction for unrestricted movement
Flatlock seam construction