IdealasUnder suits or Alone for Good Sun Protection. Madewithmaterial that provides UV protection of 50+. The seams, sewn with flatlock stitching, won't leave marks on the skin. Perfect to wear underneath your suit and ideal for all kinds of watersports. These shirts are a great first layer under wetsuits or a great stand alone shirt for the beach, lake or pool. If you want a loose fit, order a size up. Excellent for wearing under your wetsuits or stand alone. Under your wetsuit, it helps you get your suit on because the lyra glides. Hyperflex Mens Long Sleeve Base Layer Rashguard, Adult