The only bottle that features an ergonomically shaped bottle plus insulation. Fits perfectly in hand and easy to squeeze to get the perfect amount of water every time. Plus, TPU grip keeps bottle in place despite hand sweat. Fit & Design: 18oz ergonomic flask designed to be easier to squeeze Insulated bottle No grip hand strap, designed for more comfort on the back of the hand High flow Push-Pull Blast Valve(TM) cap has a quicker rebound to keep you hydrated on the go