I recently purchased a pair of TYR Fusion 2™ Jammers. After having worn them in a swim workout, I can now give my assessment.
Overall, I really like the product. If you are going from a brief or a regular jammer you can get 1-3 second per 50 increase in speed. That is significant. The design doesn't absorb water so I suspect you get a little boost just from buoyancy. The rest is the slick nature of the fabric. Its almost like a swim skin. Very cool to touch.
I will caution that although it fits true to size on the waist the bottom of the leg opening, near the knee, is tight to the point of being irritating. When I first tried to put on the suit I was thinking, "you have to be kidding me" as it was so tight getting over the knee. But the upper is true to size at the waist.
The technology uses some of the most advanced aquatic engineering to ever enter a pool. First, Tyr took existing, proven and patented technologies like Turbulence Control and TYR's unique water-repellent coating in order to reduce drag. Then they married it to their tried-and-true innovations such as Fabrication Logic and Fluid Channel Dynamics for superior flow. Add in their unique, calenderized Isolated Compression technology for more glide efficiency and less drag, and you have the new TYR Fusion 2™. It's what happens when the past and the future meet at the swim lab.
Price: $72.00, unless you have a Lifetime Member Advantage 40% discount!
This is not a every day suit. It is built for racing. It has a short lifespan. But for the occasional speed workout or if the race water temperature negates the use of a wetsuit (78F or above), you could do much worse than swim in this jammer.