- Made for Cat Series Refractors
- Comes with a M48 Filter Thread
- Used as an upgrade for first generation Cat Series Scopes
- Includes push screws and pull screws
- Focuser Threads: M63
- Diameter: 2.5"
- Compatibility: William Optics Z73, Z103, Z126, GT71, and GT81, as well as all WO focusers with M63 threads
William Optics provides quality refractors, mounts, and accessories such as eyepieces, diagonals, and mounting hardware for amateur astronomers around the world. The CEO of the company is David Yang, an avid amateur astronomer and bird-watcher who feels strongly about offering premium optics to everyone with an interest in astronomy or nature, and not just to those with plenty of cash to spare.
When William Yang was a child, he thumbed through the pages of Sky & Telescope magazine and gazed at the beautiful images of our universe laid before him. His family could not afford to buy him a telescope, but he could dream of a day when he would be able to photograph galaxies and nebulae like the astrophotographers he admired so much. In 1986, David saved up all summer to buy a telescope to watch Halley's Comet, but before that he tried his hand at building his own telescopes with whatever supplies he could find; he even "borrowed" his grandmother's eyeglasses to use as the lenses for his first refractor!
In 1996, David opened William Optics in Taiwan. Four years later, in 2000, William Optics USA began by offering their break-out 80mm Megrez refractor to consumers in the United States. The quality, as well as the price, was amazing, and before long, William Optics had positioned themselves as one of the world leaders in fast, highly portable quality refractors.
William Optics also makes some great telescope accessories. Their WO Diagonals are celebrated the world over for their machining and optical quality, and their Ultra Wide Angle (UWA) and Super Wide Angle (SWA) eyepieces, with their unusual jet-black insertion barrels, have come to be known for their quality, but at an affordable price. We think William Yang has achieved what he set out to do; providing "More Quality for Less Money"; and we look forward to what he plans to do next!