Underworks Men's Cotton Performance Compression Muscle Shirt CottonSpandex Sizes: Sizes: Measure Chest: Small 32-35 / Medium 36-39 / Large 40-44 / X-large 45-48 / 2X 49-52 / 3X 53-56 Small 32-34 / Medium 36-38 / Large 40-42 / X-large 44-46 / 2X 48-50 / 3X 52-54 SPORTING SHIRT IN STRETCH COTTON COMPRESSION - Provides an athletic look and great feel of cotton FLATTENS GYNECOMASTIA - KEEPS YOU ALL TOGETHER - Prevent bounce during sporting activities GREAT BASE LAYER UNDER A BUSINESS SHIRT - Feel slim and trim all day in any business attire MADE IN THE USA - High quality construction and made with the finest materials for maximum durability and service to you The feel of cotton and the stretch and fit of spandex are merged together to stretch and conform to every curve of your body and move with you and fit you like second skin providing you unmatched comfort, fit, and durability. The most comfortable all day underwear. Made in U.S.A. Increase blood flow for faster warm up and greater oxygen to m<span class="a-text-italic">uscle </span>tissue Can reduce m<span class="a-text-italic">uscle </span>fatigue and soreness. Made in USA <span class="a-text-bold">MEASURE YOUR CHEST:</span> With arms down on side, take a snug measurement around the fullest part of your chest over the nipples. <span class="a-text-bold">HOW TO WEAR:</span> Hold both straps of the shirt and step into the garment. Pull up the garment and slide arms through armhole and adjust for comfort. <span class="a-text-bold">HOW TO CARE:</span> Wash in cold water, gentle cycle, tumble dry low or flat dry. No bleach, no iron.