This is the ProTek R/C "Fast Fill" 500cc Fuel Bottle. The Fast Fill fuel bottle's 500cc graduated reservoir holds enough fuel to last the duration of a long main event, while the super soft material makes it easy to fill your tank quickly. At 4.5" the blue-anodized spout is long enough to reach through any opening and find the tank. A rubber cap is included to prevent spills and keep dirt out of the bottle, and the cap is tethered to the spout so you won't lose it.
ProTek R/C is an A Main Hobbies brand.