Focusing Helicoids

back brass threaded insert preferred

• M42 10-15.5mm $19.99 + 1.50
  

• M42 12-17mm $19.50 + 1.50
• M42 15-26mm $19.49

• M42 17-31mm $23.99 + 1.50
  

• M42 25-55mm $26.99
• M42 36-90mm $29.99 + 1.50