SKLZ Dual Swivel Tennis Ball Launcher, Multipurpose Trainer, 15-Foot Kinetic Cord, Ages 7 and Up

This is my third tennis trainer, first one I had when I was a teenager so that's 30 plus years ago, the second one was about 15 years ago and now this one. The first one I had had a nice springy ball that had a great bounce to it. The second one, which looked identical to the first one I had, the ball was a dud and you had to really whack it to get it to go and was very hard keeping it going. This one comes with a nice weighted base that can hold two balls and has two balls with it. I was pleased that they have the good bounce that the trainer I had as a kid had. The elastic cord seems to be of good quality, better than the two other trainers I had and hopefully will last pretty good.Now, as I said, I'm 30 plus years older than I was when I first use to gleefully play with a tennis trainer so I don't have the legs or the arm strength that I used to (or the stamina). I'm also now using it on a dirt driveway with rocks sticking out here and there so it's a bit harder for me to get the ball going and get a good rally going. As I've only had it for two days now I do think that will improve - did better today than I did yesterday with getting some good rallies going. Makes it a little harder to do that when the ball hits the random rock sticking up instead of the dirt driveway and bounces off in some weird direction but that's not the fault of the tennis trainer, just the condition of the surface it's being used on.The base is black and is flatter than the original two trainers I had so the ball hasn't been hitting that as much as I had it hit the old trainers which stuck up a bit higher. The extra ball I ended up sticking in my pocket because it kept falling out of the holder when it was occasionally hit so next time I'll leave it in the box instead.I know some have said they've had a hard time getting the ball high enough and staying high and that they keep coming back too low. My suggestion would be try different spots to try and start off in. You may be standing too close to the trainer and what works for me is to stand two to three feet behind it and do an over head serve to give it a good start. When I've tried bouncing it off the ground to hit it to start or and underhand shot to get it started I don't have as good results as I do with the over head serve. And keep trying and don't give up too soon, they do work, just need to figure out how hard to hit and the sweet area to stand in.I read all these reviews and the reviews from the couple of other tennis trainers offered on Amazon and read someone saying these are just a gimmick item that they re-release every so often because they don't work. Well, I'm someone who has used them over the years and they do work and can be a lot of fun and a great workout. I've never tried them with another person so that's something I'm interested in seeing if it works out well but I do know they work and aren't a gimmick.This one also cost more than the other two listed. One was one that you had to put sand or water in to help weigh it down but it didn't say how much weight that would add to it and the second one was more of a square block with a slot to put the ball in and the elastic seemed to attach at the end and also weighed less than this one. As I know having a weighted base works best, and liked the elastic being attached to the top of the ones I had prior and the fact that this came with two balls I figured I'd pay the extra money for it and get this one and am glad I did. Didn't have much issues at all with it sliding around, like knowing I have an extra ball and like that it is lower to the ground than the other two appeared to be.Would definitely recommend it! Wish Amazon offered replacement balls for this unit (the other one listed has replacement balls but I know these ones are pressurized and have a good bounce and don't know if the other ones balls are the same).

You have to understand - I SO wanted this product to be what it claimed to be.I purchased this the end of March 2015, but just opened it up today. The driveway was clear of vehicles, so I had the required 50+ ft radius (not really needed, but does ensure no damaged things). The attached yellow ball felt firm, the stretch string securely attached. I placed the base on the concrete driveway, stepped back about 12 ft from the base, and smacked my first shot. The return is deceptively quick - so much so my first attempt at a 2nd hit ended up jamming me and hitting off the side of my racket. The bounce was adequately high for the stroke I used. I tried another, getting into position much quicker and managing a couple return rally's. This this was AWESOME. The tennis junkie in me was smiling, my Loseit app gearing up for a calorie reduction entry. I hit a 3rd shot, the ball taking a lower bounce back and throwing me off guard once again. I reached down for the ball thinking I had finally found what I had been searching for...That's when the wheels fell off this wagon.After 3 rally's, 6 or 7 hits total, the ball was completely FLAT - no bounce to it. I squeezed it a little and realized that it had actually split about halfway around the ball (under the felt), like it was a perforated seam designed to self-destruct. I was devastated, but felt sure it was a fluke and the other ball would be better. I walked over to the box and pulled out the "instructions" - there were no instructions on how to put the replacement ball on. A quick Google search revealed that a "parallel knot" was required. I removed the now destroyed ball (having to cut it off) and attached the new ball on. I couldn't recreate the little knot size the original had, but it was close enough (entire process took about 15 minutes). I went back to my spot and resumed my hitting. The 2nd rally attempt (the first was as glorious as the first one on the first ball) the ball and string shot off towards my house and kept going till it hit my roof. I quickly realized it had detached from the base. A quick examination revealed the little plastic swivel piece had broken off. With no other choice, I just took the loop already there at the end of the string and placed it in the same clip that attached to the base. It wasn't "tangle free" anymore, but at least it was attached. 2 more rally's in and the ball stops bouncing... AGAIN... Same situation, except this time there is actually a tear and hole present on the ball. After 7 rally's (5 with multiple hits), both balls and the tangle-free connector are destroyed.Other issues - after the 2nd ball bit the dust, I did continue to try and hit it a few more goes. The base does slide around. I managed to position it behind a raised lip in the concrete, but you would prob want to secure it somehow. I did (out of desperation) too a new tennis ball and made my own replacement. I followed the advise of another reviewer by taking an old shoelace, creating a knot with a loop (I used the same parallel technique) and forced the knot into a tiny hole I created with a little electronics screwdriver, leaving the loop sticking out of the ball and attaching to that loop with the string. Being a pressurized ball this wasn't the ideal choice, but it's all I had close by. This worked decent enough (the ball stayed on the entire 25 minutes of constant, hard hitting), but all the extra knots and such take a toll on the smoothness and you notice the string a lot more than you did on the original setup (for all the 2 minutes that lasted). I managed a decent workout, which is my main goal for this contraption. I plan to go purchase some non-pressurized balls and attempt another go at it. The company has been "sold out" of replacement balls for over a year, and you cannot find any online anywhere (if the quality is the same it's a moot point anyway).I really can't comment on it as a "trainer" - form and technique really don't help as much as power and speed, and the best stroke to keep the ball going would send the ball on an actual tennis court over the back fence hitting some poor grandma out walking her dog. But, because walking is boring and tennis partners are harder to find than ball replacements for this piece of junk, I will most likely continue to try and use it. If you are on the fence about this product, for the love of Baby J just walk away.