Non Rotating Helical Focuser with M52 connection

The advantage of this helical focuser is the fine adjustment with high precision, combined with little height.

• precisely adjustable
• limitedly self-locking
• M52x0.75 threads on both sides
• 48 mm clear aperture
• minimum optical height 25 mm
• 30 mm focussing range (max. optical height 55mm)
  
• can be used as a variable M52 extension for 2" focuser
  
• distance indicator with 0.1mm scale for reproducible focusing