As any berry connoisseur knows, the taste of a blackberry varies throughout the season. The taste of Jet Blackberry is like that mid-summer berry: ripe enough to deliver unmatched sweetness while still bringing out a touch of tart. It won’t make your mouth pucker, but it keeps things interesting. This flavor also packs 40mg of caffeine – to help you turn on the jets, of course. To avoid bonking while exercising, you need a portable source of easily digestible carbohydrates to fuel your muscles. GU Original Energy Gels pack quick, effective, and sustained energy to meet the demands of all types of activity. All Energy Gels are Vegan, Gluten Free, and Kosher.