The Psycholist SL Water Bottle is incredibly light weight coming in at 54 grams and 550 ml. Fitted with a high flow nozzle you can really keep yourself hydrated and not carry any extra weight. With the ultra light bottles the sidewalls are thinner than normal for ease of drinking. These bottles are slightly smaller than your standard bottle. If you need to pack more water on your rides we suggest using a larger size Bidon.