I have been using the Wellos laundry balls for three weeks now and can not fault them in any way. I have used a number of different types of balls which I have always considered to be good, but these ones I would class as excellent. Two members of my family have skin problems which is why I considered getting rid of soap powders and using the laundry balls instead, and this has worked we no longer have the constant itchiness and wanting to scratch all the time. The old balls were good, but needed topping up with the small balls regularly. Some were easy to open, but could cause a problem later and open in the machine emptying the contents into the laundry. Another type has to be opened with a screwdriver after removing a sponge collar from the ball, and very difficult to replace the collar. The Wellos ball is guaranteed for three years, so far I have bought two of them which I alternate to make sure they dry out between washes. All clothes have washed beautifully, anything that is stained is soaked for a while in a stain remover, then washed. I have recommended these balls to my family and friends, can't praise them enough.