The Vello T Mount Lens to Sony Alpha Camera Adapter allows you to attach a T mount lens to a Sony Alpha camera body. You can also use it to mount your camera onto a telescope that has a T mount. The all-metal adapter is designed to fit the lens securely, yet can still be removed easily when not needed. It has a secondary ring inside with three positioning screws enabling adjustments to make sure your lens is straight. Focusing to infinity is retained.