This is a very nice high power eyepiece. gives the widest viewing field along with extra sharpness and long eye relief. Threaded for standard 1.25 inch astronomy filters and barlow lens. Comes with sturdy plastic case-proect the eyepiece from dust and moisture. Soft rubber eye guard that's custom fitted with a bayonet mount. Perfect for broad-field lunar observations, medium-sized star clusters, and a wide range of cloudy nebulas. Specification: The Structure of the Optical System: Plossl Eyepiece Coating: Fully Coated Height (Total): 50mm colour: black Material: Metal size: 31.7mm Package Contents: 1 * Plossl 4mm Eyepiece 1 * Plossl 6mm Eyepiece 1 * Plossl 9mm Eyepiece Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.