Telrad Mounting Base Only - 2001 type-astrophotography-and-imaging-accessories It can be used either

It can be used either way

Secondary Mirror Obstruction by Area: 9

8"(2032mm) f/10 Edge HD includes StarBright XLT coatings for better light transmission

It's gear ring has 153 teeth

Telrad Mounting Base Only - 2001 type-astrophotography-and-imaging-accessories It can be used eitherTelrad Original Mounting Base Only Extra Telrad Original Mounting Base Use your Telrad Finderscope on another telescope Base attaches easily to telescope with adhesive strips Buy a spare Base for each telescope you own Use one Telrad Finderscope with all the scopes you have This is an original Telrad Mounting Base, only. If your mounting base gets damaged, this is the perfect replacement one. Or buy one or more of these Telrad Original Mounting