Zhik spandex rash guard top, great for layering or wearing alone. Fully functional, no rips or tears but shows signs of wear (pilling) on arms. Retails for $63 new. See size guide in photo for reference  
Description from Zhik website: 
Zhik Eco Spandex tops provide comfort and everyday UPF 50+ sun protection in the warmest of conditions on the water. The incredibly lightweight coverage combined with 3D body panelling allow for a dynamic and comfortable fit which conforms to the body as you move.