1,STANDARD SIZE: This is a standard 1.25in telescope universal eyepiece, can be installed with standard 1.25in astronomical filters and for Barlow lens 2,WIDE FIELD OF VIEW: The 1.25in 15mm foldable eyepiece provide the widest field of view, extreme sharpness and long eye distance, useful and practical 3,APPLICABLE SCENARIO: 4 lens astigmatism design, with about 50 degrees of field of view. Ideal for wide field lunar observations, medium sized star clusters, and a variety of cloud nebulae and deep space targets 4,ERGONOMIC DESIGN: The eyepiece will have a soft eye mask so that the eye can comfortably touch the eyepiece while viewing. Come with a sturdy plastic lens housing that protect the eyepiece from dust and moisture 5,MULTILAYER COATING: Fully coated optical glass eyepieces provide excellent image contrast and transmittance; Provide maximum detail and clarity across the entire field of view; Highly chromatic aberration; Planetary filters enhance details of Jupiter, Saturn, Mars and Venus Item Type: Telescope Eyepiece Material: Aluminum alloy and optical glass Focal Length: 15mm Field of View: About 50 degrees Interface Specifications: Standard 1.25in/31.7mm Lens Coating: FMC green film Number of Lenses: 2 Sets of 4 pieces Thread Specification: M28.6X0.6mm 1 x Telescope Eyepiece 2 x Dust Cover(pre installed) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store