ACHIEVE PERFECT FOCUS - Fine-tune your astrophotography with this kit's three precision spacer rings (7.5mm, 12mm, 30mm), ensuring optimal camera sensor placement for sharp, detailed images. MAXIMIZE IMAGE QUALITY - Eliminate unwanted vignetting and aberrations by using these M42 spacer rings to precisely adjust the distance between your camera and telescope optics. ENSURE COMPATIBILITY - Designed for seamless integration, these M42 spacer rings are compatible with a wide range of astrophotography cameras and telescopes featuring standard M42 threads. CUSTOMIZE YOUR SETUP - Adapt to various telescope and camera configurations using the included spacer rings, allowing for flexible adjustments to achieve the ideal back focus distance.