The red filler cap with a lanyard is an alternate provided in the Jersey Modeler jet kit. The vent plug is 'T' shaped with a "Remove Before Flight" flag. Been using the same filler cap on my AreS XL for about 100 flights with no problems. All fuel lines are safety wired except for where the tygon line from the filler cap goes into the UAT where it has a screw-on clamping sleeve.