1STANDARD SIZE: This is a standard 1.25in telescope universal eyepiece, can be installed with standard 1.25in astronomical filters and for Barlow lens 2WIDE FIELD OF VIEW: The 1.25in 15mm foldable eyepiece provide the widest field of view, extreme sharpness and long eye distance, useful and practical 3APPLICABLE 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 4ERGONOMIC 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 5MULTILAYER 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