The Jackson Kayak Happy Feet Foot bag: Large and XLarge is going to change the way you think about comfort and adjust ability in a kayak. Tuck your feet into the bean bag and get them super comfy, then close the valve and you have your footprint proudly placed in the Happy Feet Footbag. Then pump the bulb which inflates the adjustment bladder and you will tighten up bag until you have the right amount of pressure to give you the control you like. Get to the bottom of the rapid or pull into an eddy and hit the release valve, now you have extra room again and can lift your knees out easily to relax.What size Happy Feet Footbag do you needYou will need to remove the existing footbrace from your kayak. Once you do that, how much foot room do you have If there is not much wiggle room around your feet, get the Happy Feet Large. If you do have some space, go for the Happy Feet XLarge. If you are having trouble deciding, you can always get a Large bag, and add minicell inside the bow of the boat to bring the bag closer to you.