GSO [ Made in Taiwan ] 6x30 achromatic finderscope is a good choice for any telescope, both astronomical and terrestrial. It shows stars to 9mag. The finder has an achromatic 2-element objective with 30mm aperture.
The metal diecast mounting bracket allows a very comfortable adjustment with 2 screws. The bracket fits most of the branded telescope. With the optional dovetail finder mount, you can adapt the finder to nearly any telescope. 
Specifications:
Achromatic Objective - 2-element with 30mm diameter
Bracket - adjustable with 2 screws - spring system
Aperture 30mm - Magnification 6x with cross hair eyepiece
artifical field of the eyepiece ... 45°
Real Field in the sky ... 7,5°