WRELS hydration bottle, 500ml, with a 4cm wide mouth for easy ice insertion. Photos 6-8 show the one I personally use, compared with a SALOMON flask. - Brand: WRELS - Capacity: 500ml - Mouth diameter: 4cm Set of red and blue logo bottles. New, unopened. Returns and exchanges accepted only for initial defects. Please fill with water upon arrival and check for leaks after properly closing. To reduce any odor, dissolve 15g of baking soda in hot water, cool to below 40°C, and then put it in the flask overnight. This will alleviate the smell somewhat, but individual differences may exist. Thank you for viewing. Soft flask, soft flasks Salomon, SALOMON, The North Face, Hydrapak, hydrapak, trail running, trail run, mountain climbing, hiking, backpack, rucksack, ultra, marathon, triathlon, cycling Capacity...500-999ml