***** **********Best Quality Guranteed. *****Fully multi-coated prisms for superior image fidelity and maximum light throughput; Effectively reduce the light loss of your light during transmission to improve the brightness and color saturation of the image*****Correct upside down and left-right reversed image easily; Even if you want to observe wildlife or other scenery during the day; SV138 diagonal mirror can also easily provide you with the right image*****High quality CNC manufacturing; aluminum alloy housing and stainless steel cover; Extend SV138 diagonal mirror life and make it more durable without worrying about damage during use*****Unique brass ring design; Provides a uniform pressure-receiving area when holding the eyepiece; not only is it fixed more firmly; it does not damage your expensive eyepieces*****The SV138 45-deg correct-image diagonal requires 5/8" more focus travel than typical diagonals; Not recommended for use in Newtonian reflector or Dobsonian reflector telescopes