Double shoulder straps: 98% of the lightweight shoulder bags are double shoulder straps. The double shoulder straps are designed to support the back for balance and reduce fatigue.
Easy to unload: Not all shoulder straps are easy to remove, some are fixed too well, and it is quite painful to use.
The feet are strong: the feet must be light and strong, easy to open and easy to fit, even on uneven ground.
Reasonable separation: 5 small bags on the bag are the best. A ball; a ball T, a repair fork, a ball mark, etc.; a glove, so you don't have to roll them into a mess; a raincoat, so it must be big enough; the last bag is mixed Object. Too much bag will increase the weight, too little and not enough.