Here's what other sites are saying:
The GU Flask combines squeeze-tube convenience with 5.5 ounces of GU (that's five packets, enough for a 5-hour workout). The Flask's clear plastic body lets you see how much of a charge you've got left, and it's dishwasher safe, too. Clear in color with GU logo. Weighs 0.6 ounces.
- Altrec Outdoors
The GU Flask combines squeeze tube convenience with 5.5 oz. of GU (fill with 5 packets of GU (not included), enough for a five hour workout). The flask's clear plastic body lets you see how much of a charge you have left and it's dishwasher safe too.