High-quality zoom eyepiece provides good high contrast view. Feature multi-coated optics allowing high contrast viewing. Sky-Watcher zoom eyepiece is well constructed providing a sharp and crisp image with excellent eye relief. Support all standard 1.25'' size telescope barrel. Threaded for filter attachment zoom eyepiece allows multiple different magnifications from a single eyepiece. Work great to change from wide angle viewing to high power viewing from a simple twist. Full metal construction ensures durability.
If you are looking for a high-quality affordable zoom eyepiece, Sky-Watcher 7-21mm zoom is an excellent choice!