This is a brand new Ultimate Direction Ultra 4.0 Hydration Vest - Size: Medium

I purchased this, removed the tags, and filled the bottles to compare this to a fuel belt.   I ended up deciding to not use this vest.   

From the UltimateDirection Website:

"Lighter and sleeker without compromising functionality" –Ultrarunning Magazine 
For serious runners that put training and racing in the same order of importance as work and family, the Signature Series Ultra Vest is your ally. Turn your wildest and most ambitious race goal into reality with this 10.3 liter do-it-all vest. MicroMono mesh fabric with 4-way stretch nylon eliminates irritation from sensitive spots like shoulders, neck, and ribs. Two bottles up front provides a liter’s worth of water or sports drink with enough additional capacity for a phone, camera and trekking poles.

Specs

  • Bottles Included: 2 Body Bottle 500s
  • Reservoir Compatible
  • Volume Capacity: 629.76 in3 / 10.32 L
  • Weight With Bottles: 10.72 oz. / 304 g 
  • Weight Without Bottles: 7.27 oz. / 206 g
  • Reservoir Compatible: 50 and 70 oz (sold separately)

Sizing at Bottom Ribs (Unisex):
  • MD: 30 - 39 in. / 76 - 99 cm