The Airlock, or ventilation closure, blocks the tailgate, leaving it ajar, allowing air circulation to avoid heat in the T3 when it is parked, if we leave animals inside, to sleep in the summer... the one sold in other stores me They commented that it was too long and that not one, but both arms could be put inside the van, so we have manufactured this other one, which is 5cm shorter and does not allow the entry of the arm.