Only complaints I have with the product is that the quick connects from the pump to the ice bladder will sometimes be frozen due to re-freezing and won’t connect until properly thawed. Straps on backpack when first sizing for one body size is cumbersome but not a concern after sizing. Thermal cooling capacity lasts for about 3 hours using a fully frozen 5L bladder (11 lbs), which assumes that the bladder will turn from ice to room temperature water in a room slightly higher than room temperature. Backpack offers two sets of hoses to install two ice bladders instead of one to double duration of cooling at the cost of added weight, if you prefer to use/switch to one bladder at a time I’d suggest a smaller product. Purchase of extended hose is preferable if you want to continue cooling without consistently wearing said backpack in small spaces/sitting down as weight will be felt on tail bone/lower back when sedentary.
