The Union harnesses is one of the lightest harnesses on the market, it weighs just 1.1 KG. The Union "padding frame" is made out of just one piece, this saves all the weight and eliminates stitching. This construction is making the harness exceedingly durable.
Manera has putted an "energy dispension frame" over the padding frame to perfectly spread all the power over your back. This works very well and provides a very comfortable ride.
The "Tuck flaps" which are attached to the spreaderbar are preventing it from riding up, and it stiffens the harness for better support.