Introducing the William Optics UNIGUIDE 50/200MM Guidescope Bahtinov Focusing Mask, a must-have accessory for any telescope enthusiast. This Bahtinov mask is compatible with William Optics telescopes and features sharp, long, bright beams to guide your viewing experience. The mask has a diameter of 58mm and is suitable for use with any focal length. Its series, Uniguide 50/200mm, ensures precise and accurate guiding for your telescope. This Bahtinov mask is the perfect addition to any telescope setup and will enhance your viewing experience. Its features are optimized to provide clear and crisp images, while its compatibility with William Optics telescopes ensures a perfect fit. Invest in the William Optics UNIGUIDE 50/200MM Guidescope Bahtinov Focusing Mask and take your telescope viewing to the next level.