To Buyers: We are having trouble with many people not pressing the evaluation button after their packages arrive. Please press the evaluation button. No discounts are offered. Price negotiations are not accepted. You cannot choose the color of the flat string. As you can see, this is an original triple knock machine (shuttles not included). It takes out 3 shuttles at once, increasing the efficiency of knocking. Similar products are available, but mine is the original, so please don't be mistaken m(__)m Single-tube and double-tube versions are made as originals by anyone, anywhere, but my knock machine, which can simultaneously extract and hit three shuttles, is the only one of its kind. The officially sold ones are expensive and heavy, so I made this original. Mine is light, with the tube weighing about 310g. The tube can hold 60+ shuttles. With each shuttle weighing 5g, 60 shuttles weigh 300g, so the total weight is about 610g. I am also a coach, so I use this at elementary, junior high, high school, and corporate teams. Elementary and junior high school students have smaller bodies, so it's well-regarded for being light, reducing the burden. The students say it's really easy to use because they carry it themselves, and they've even won the junior high school district tournament and the block tournament above that. It's skeletonized, so you can see the contents easily. It's also easy to refill the shuttles. The length is 54cm-55cm (because it's handmade). The longer the length, the more the tube moves, making it difficult to use, so I made it this length. The length of the flat string is adjustable, so it fits your body and the tube doesn't move, making it easy to use. This is an original knock machine that can be used by children and adults. Available for purchase. YONEX Yonex Mizuno Wilson Prince Li-Ning Gosen Black Knight Apacs Badminton Shoes Shuttle Racket Wear