Gill Rash Guards are made from a high quality 4-way stretch lycra and come in a number of color and style combinations. All Gill Rash Guards offer excellent UV protection (UPF50+), are quick drying and have flat locked seams for reduced chafing.áGill 4421 Men's UV Sport Rash Guard Short Sleeve Features: 6oz 4 way stretch fabric for comfort and fit. Lycra fabric - more durable than polyester. Can be worn as a layering piece for comfort or alone on warmer days for sun protection. Durable stretch print detailing. Sizes based on Men's Sizing Chart.