The Caliburn Tenet Koko is a square shaped device just like other Caliburn Koko pod vapes. It`s 73.7mm tall, 50mm wide, and 18mm thick. This makes it slightly larger than other Koko devices and it feels a bit more bulky in the hand.The Caliburn Pod System from Uwell is a pocket-sized refillable pod device made for nic salt vaping, but which can also be used with both regular nicotine or no nicotine at all. It uses both button and draw activation and comes with a built-in 520mAh battery.