I needed an interval timer that could 'grow' with me during my weekly fitness regimen in and out of the gym. But first I had to figure out how one operated in order to know what I was looking for. This was a trial and error process for me. I first tried the GoFit Go Interval timer. I realized that the interval times were pre-determined to 30, 60, 90, and 120 second intervals. And the sets -or rounds - were also pre-determined, but in minutes. The Gymboss miniMAX allows me to select how long I want to, for example, hold a stretch, rest between the next stretch, and for how many sets (or rounds) I want to repeat these intervals. I can use it for circuit training. I can also use it for the Calloway run-walk-run method: I set this timer to allow me to run 5 minutes, audible beep and/or vibrate to signal walking two minutes, and then an audible beep and/or vibration to repeat this sequence again.I can save my static stretching and circuit training as P1 (Program 1) and P2, and my run-walk-run times as P3 (Program 3). This is a nice feature, because I just have to select a saved interval session without having to re-enter the information each time I want to use that timing sequence again. I could even add a P4 to alert me by vibration in 4-minute intervals of my progress while doing a recreational cycling time trial or sprints. I just thought of this!I can save up to 20 programs. Intervals can be set from 2-99 seconds and can be repeated up to 99 times. Another feature I like is that I can set the alarm as either loud or soft (indicated as a capital 'B' for loud and a lower case 'b' for soft on the menu display). And I can also set this timer to vibrate strong ('V') or gentle ('v'). Or I can choose any combination of these choices (e.g., beep and vibrate simultaneously).If that isn't enough flexibility to get excited about, it also has a clock and a stopwatch, and comes in several different color combinations. I chose the camouflage style.I reviewed, purchased, and returned several timing products, that either had too much or too little of what I was looking for. And some were just too large in size. I did not initially order the Gymboss MiniMAX because it was not listed as Amazon Prime; I wanted guaranteed two day delivery. I decided to compromise longer shipping for a product that might be 'the one.' I ordered Wednesday morning, and it arrived Saturday morning - just in time to head to the gym with it!My Final Evaluation: this timer is worth the additional cost for its flexibility of features, small size, and clip. I also ordered the Gymboss armband sold seperately. I included some instructional detail in this review, of information that I found confusing at first, as I tried reading the simple, but microscopic printed instructions. I recommend this timer with full enthusiasm, and I will definitely be bragging about it to my fitness buddies where interval training is important. It turned out being just the timer I needed!