Not sure from picture but you definitely do not want a gravity one you want motorized one that uses ice and water, plugs in the wall. Make sure if you are having a TKR to get the knee wrap if you are have shoulder surgery get the shoulder wrap. We just bought 4 bags ice from store prior to surgery and it will last a good long time. Think we refilled it once day but our cooler part was larger than your picture
Hope this helps