The Riser Base is used in conjunction with the existing mounting base, it acts to offset the sight from the main tube to increase eye relief.
Reviewed by 2 customers
As with all of my other Telrad products this one is also of fine quality and easy to install. It enables me to use my Telrad finder in addition to my scope finder without straining and without knocking my head or eye into my scope finder by elevating the Telrad 4" from the OTA. The Riser Base is easily detachable and attachable and also the Telrad is easily detachable from the Riser so I can easily remove my Telrad and use it on another telescope. The Riser seems very sturdy and should serve me well for many years.
This unit sure does save my neck in looking at the skies on my 10" DOB