An optical cage system uses four rigid steel rods to mount optical components along a common optical axis. Cage systems are available with center-to-center rod spacings of 16 mm, 30 mm, or 60 mm so as to accommodate Ø1/2", Ø1", or Ø2" optics, respectively. Thorlabs provides an extensive selection of accessories for the optical cage system as well as adapters that allow the user to switch back and forth between the three different cage standards offered. In addition, the optical cage system can be integrated into optical setups using mounting posts, lens tubes, or one of many other mounting options.