How to choose a good cooler bag.A soft-sided cooler has to be portable enough for you to take where you want. It also needs to be large enough to hold enough drinks and food.Stylish but sturdy, the Hopper Flip is made from Yeti’s trademarked dry hide shell. This is great if you take the cooler with you any place where water is involved. It’s fully waterproof, resistant to UV rays, puncture proof and mildew resistant.While traditional hard coolers are typically more durable and can keep things cold for days, they can be difficult to transport easily. Soft coolers are made of lighter materials and designed to be carried.