Get the party started from the very beginning. This is by far the coolest proposal you could give to your groomsmen. It'll be a challenge that they can't refuse. Put your favorite drink inside and ask your future groomsman to chug. Take the labels off after and they will have an amazing personalized cooler that they can use at all kinds of events, from tailgating, BBQ's or any other excuse to bring some drinks.
The cooler is made of 600-Denier Polyester with a PEVA (PVC free) lining, meaning this cooler can you keep your drinks cold and your food warm. The cooler can hold up to 12 bottles or 18 cans. It features both a top padded carry handle as well as an adjustable shoulder strap with a front pocket for storage. For an added bonus, there is also a bottle opener on the side. Add your guys initials and there you have it, maybe the world's most awesome proposal gift.