The SKLZ Gold Flex is a rival of the famous "Orange Whip", sold $ 109 in the US, and found in Europe at this price. You have to add shipping cost prohibitive in case of direct control, which leads to a price +/- 130-140. The Gold Flex 64 then became a must, especially since he apparently did the same thing for half the price of the Orange Whip, judging by the trials that I found on various European and US sites . It is perfect for warming up before a journey, and intuitively learns the right rhythm, especially the famous transfer of weight on the left leg, the passage of the hands and the right position at the end of swing. It does not need to wait for the miracle solution to immediately correct swing, but it helps to understand "the right thing". Good buy for me, especially for this price. Would recommend,