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30mm Diameter x 15mm Length, Cage Extension Tube

30mm Diameter x 15mm Length, Cage Extension Tube, #85-590

Stock #85-590 In Stock
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C$43.40 C$30.38
Qty 1+
C$43.40 C$30.38
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Fixed Tube
Compatible Plate Inner Diameter (mm):
Dimensions (mm):
30 Dia.
Length (mm):
Thread Type:
M27.5 x 0.75
Black Anodized Aluminum
Outer Diameter (mm):

Regulatory Compliance

RoHS 2015:
Reach 224:
Certificate of Conformance:

Product Family Description

  • Fit within Inner Diameter of Cage System Plates
  • Use with Retaining Ring Pairs to Secure Optics
  • Join Multiple with Adjustable Length Tubes and Thread Adapters

M23.2 and M27.5 Fixed Extension Tubes are ideal for covering portions of the cage system. Each fixed extension tube is designed to fit within the inner diameter of a cage system plate, and feature either M23.2 x 0.75 or M27.5 x 0.75 female threading throughout the entire length of the tube. Retaining ring pairs can be used to secure optics within the extension tube, while adjustable length tubes and thread adapters can be used to connect fixed extension tubes for building customized optical assemblies.

M23.2 and M27.5 Tube System Retaining Rings feature a thin, 3mm thickness. They are sold in pairs, and are ideal for securing optics within extension tubes. Each retaining ring features an optic shelf which centers the optic within when sandwiched between retaining ring pairs.


#85-582 threads into a M23.2 x 0.75 standard tube to easily mount a plate beamsplitter. #85-539 fits within the inner diameter of cage system plates; it also threads into a M23.2 x 0.75 standard tube.