When this bottle showed up on my porch, I was heading out to the golf course...so I did the irresponsible thing and just took it along. Quickly unpacked it, rinsed it, filled with water and headed out the door. In retrospect, I really should have taken the time to do an initial inspection and closer examination before using it .... but, oh well..!!  This bottle holds 20 ounces which is the size of one of the large soft drink bottles in the refrig. case at your local convenience store. It lasts about half way around the golf course on a warm day, so you can stop at the clubhouse and refill before heading out for the back nine.