HydraPakSP558HP SkyFlask Speed 500ml Malibu Blue 500ml

This was sent by Parcelforce who, unlike most Amazon deliveries, didn't just use their discretion and leave it out of sight. I had to give them instructions where to leave it on their second attempt. However, it still arrived within only a couple of days of ordering it.I chose the 350mm size on the basis that I wanted to keep the weight down, and if I needed more water than that, I'd carry it on my belt or in my Camelbak.Sizes can be deceptive. It seemed so small that I actually brim filled it and emptied it into a measuring jug just to make 100% sure it really was 350 ml. It is.For those who aren't quite sure what 350 ml is, this drinks bottle holds slightly more than a standard cola can (330 ml), or slightly less than half a standard wine bottle (750 ml). On a 5 -10 k run, I find there's enough for a sip or two when my watch beeps at the end of each km, and a little bit left as a reward at the end of the run.The bottle is well made and feels tough. You can unscrew the entire top for cleaning or drying, or fill it quickly and easily with the flip top. Brim fill it, close the lid, then suck or squeeze the small amount of air out and the water inside won't slosh around. Then to drink, just bite the nozzle and either suck, or if you prefer, squeeze the bottle.The strap and thumb loop arrangement is simple but works.I watched a few videos before choosing this. There are many soft flasks for runners which come in fabric or neoprene covers with zipped pockets for keys, card, phone, etc. I saw all that as extra bulk and weight in my hand so I went for this simple and lightweight option. I'm pleased with my choice.This bottle is easy and pleasant to use, and much easier to drink from on the move than a hard bottle. Hint: if you want to drain the very last drop, bite the nozzle and blow lightly to reinflate the bottle, then you can tip the last drop towards the nozzle.Some reviewers have mentioned a chemical/plastic taste in the water, but I have not noticed anything. I'm usually very sensitive to unpleasant tastes and smells, but the water in this bottle just tastes like water. (Update: after a few runs, the taste is noticeably less strong.)A simple, well designed product.Update: so pleased with it that when the heat wave came along, I ordered the 500 ml version. Slightly bulkier, of course, but equally well designed. The more I use these bottles, the more pleased I am that I bought them.