Mac in Sac Rain Trousers Mac in a Sac is an easy lightweight nylon rain trouser, designed to roll up small in the included storage bag. The rain trouser is 100% waterproof and windproof due to taped seams. The elastic in the waist makes the trouser fit perfectly. The legs are easy to adjust with a Velcro closure, so the rain trouser fits well on your body. Specifications: Color: black Material: nylon Size: 116/122