Firstly, the product was dispatched almost immediately and arrived ahead of expectations. My initial impression was that the weighted resistance balls were too light and additionally, my first attempts at using the cordless skipping rope appeared to strengthen that belief. I also found that co-ordinating my left and right hands to achieve the correct spin was a challenge to say the least. However, within a very short period of time, about 5 minutes, I developed the correct technique and found that these are in my current opinion a brilliant addition to my skipping routine. Now, after only 2 days, I am able to achieve a seriously good workout from these. With the obvious space saving and silent benefits that they provide. And the weight of the resistance balls, perfect in my opinion. Any error (with me there are plenty) can cause you to strike your legs. With these, there is zero consequence which I would imagine would be the case with 1 kilogram weights. Highly recommended.