The Apertura AD6 is a Dobsonian-style telescope with a base designed to provide stability and support for the optical tube. The base diameter is not explicitly specified by most manufacturers, as it can vary slightly due to manufacturing differences or design updates. However, typically the base’s largest diameter will be slightly larger than the telescope’s aperture, which is 6 inches. You can expect the base diameter to be in the range of 18 to 20 inches, accommodating the mount structure and providing good stability for manual pointing and tracking. For precise specifications, checking the product’s manual or official manufacturer resources is recommended.