Beers ERT 300 Tennis Computer, Black

....and those who desire to play with the best condition equipment. These are not easy to come by, as they seem to sell out before you get a chance to grab one. I got mine and I won't let it go. What does it do? Well strings are like the cardio system of a tennis racquet. If the strings are not fresh, they don't snap back, and therefore they don't create the spin they did when fresh. This happens at differing times depending on the player, the amount of power they hit with, the racquet head size and flexibility, and the string pattern. Most regular players will see about 20-30 hours of play before the racquet becomes less playable, and given the next 10 or so hours the racquet is not playing to spec and the player will find their shots going long (not getting enough spin to create the downward force of the ball) or their kick serve not kicking up as it normally does. They start losing control, and most people will actually assume the problem is their own, and they begin to change their game/strokes, etc to accomodate what is actually happening with the racquet. This device the Beers ERT-300 helps you recognize your tension level, and monitor it as you lose tension. When the racquet gets to that 20%+ lost tension mark - you will find the racquet plays different. When it's at 25-30%, it is what the tennis stringing community calls "Bagged Out" and within a few hours after that (if you hit the ball with any amount of power) the string will have no more elasticity and it will break. So about 10-20 hours after the racquet stopped playing at optimal levels, most players will not make the change to fresh strings as they should, instead they play till the string breaks, all the while frustrated with how poorly they played this entire last week. Love this product, friends, customers, other players ask to have their tension checked. Works like a charm, it's my secret weapon! LOL

It simply doesn't work 9 out of 10 attempts. Either fails to start a measurement or comes back with bogus values. For a tool this pricey it is a complete disappointment.

This item is ok. You have to take the reading the device gives you and then use a little handheld chart with a wheel to figure out the tension, its a pain. Main gripe is that with polys and the low tension they are strung at, after a few hitting sessions, this computer can't read the tension, its below its lowest range - not good after spending this kind of money.

Important tool for any USRA stringer, or any amateur stringer as well. When used properly, the ERT can inform your decision about stringing frequency, string types, and how a hybrid string installation will perform over time compared with other options, among other bits of important info to a stringer.I've used the ERT 300 for 7 years as a professional stringer and would rarely leave home without it. After enough time using it, you won't have to refer to the conversion chart, but if you are demonstrating to a customer, it's useful, particularly if they are wanting to understand why and how different racquet sizes influence string choice and tension, etc. Disclosure: I do not have a sponsorship or other financial relationship with the manufacturer.

This is the greatest invention since sliced bread! I've had 2 of them for four years -- just to cross reference and make sure that I wasn't getting a faulty reading. Both of them still give me the exact same reading ever time -- amazing! The reviewer that said you get a different reading every time just doesn't know how to use it -- you have to follow the directions but once you do that, it is incredibly consistent. Once you know the ERT 300 value range that you want to play with, you never have to look at the chart. Also, when you tell 2 stringers to string your racket at the same tension, the actual tension that your racket gets strung at could vary by as much as 10 pounds -- and only the ERT 300 will tell you that. A racket strung on a lock out stringing machine will loosen much more than one strung on a constant tension machine -- and then there's the issue of whether the machine has been calibrated recently and the difference in how a stringer ties the knots, etc. The ERT 300 will measure the tension down to well below 40 pounds -- I've strung mine at 44 recently and it could measure that low easily --- so it's only if you want your racket strung at a very low tension that you won't be able to use it.

It doesn't work . It gives you a different reading every time. And on some racquets it doesn't work at all