The adapters are precision engineered to ensure a perfect fit. This adapter gives you the ability to use your irreplaceable fixed focal length lens and saves you the cost of buying new lenses. Made of aluminium alloy, the thread of the telescope does not damage, and the 2-layer thickened aluminium alloy is very firm. M42 x 0.75 thread is divided into an inner ring and an outer ring with double layer construction. The relative positions of the inner and outer ring are fixed with 3 screws, which makes the camera angle easy to adjust. Full manual operation, manual focusing, manual exposure, aperture priority exposure