ZWO 30F4 MiniScopeZWO 30mm f 4 Mini Guide Scope The ZWO Mini Guide Scope is a 30mm f 4 refractor guide scope in a small, easy to use package. It even comes ready to use with guider rings and dovetail for simple mounting. ZWO made sure this system was lightweight (1. 1 lb.), allowing you to use it on most any scope or mount. Add an inexpensive brand specific t ring to the ZWO Mini Guidescope and attach it to your DSLR camera. It can be used as a finder with optional