This Kyosho 500cc Fuel Bottle promotes quick, easy and clean refueling of RC nitro cars trucks and any other vehicle with a quick fill tank. The soft bottle allows you to suck fresh fuel from the fuel jug into the fuel bottle, and then the extended filling tube can reach into most quick fill tanks. After a quick squeeze of the fuel bottle, the tank is full and you're good to go until your next pit stop. This improved version features a tighter fit between the bottle and the lug that holds the filler tube. The filler tube is also slightly larger so fuel flows more quickly. Two filler caps are included (just in case you lose one) and they both feature holes to allow them to be tethered to the fuel bottle. With the extra cap safely stored elsewhere, the cap in the filler tube can be quickly removed for the pit stop. Once the tank is full, just pull the cap from the holder and place it back in the filler tube. It's that simple!