With the 509 FZN LVL1 Party Suit, there'll never be a question of who's ready for a good time. This one-piece base layer is made with a warm, hardfaced polyester with a brushed fleece interior, and can be worn under a mono suit or jacket-pant combo to help keep out drafts, snow, and party blockers. An elastic waistband keeps it in place while a near-360 zipper allows you to efficiently drop trou when nature calls.