Standard RMS Thread is for Olympus microcope objective lens thread size. Includes many Finite objectives;except eg Nikon BDs;,

M25*0.75mm Thread is for Nikon and Leica microscope objective lens thread size.25mm x 0.75mm Nikon CFI60 Infinite microscope objectives,

M26*0.706mm Thread is for Mitutoyo microscope objective lens thread size.

M26X36TPI also For Mitutoyo infinity microscope objectives and Olympus neo Splan / Dplan infinity metallurgical objectives

M26*0.75mm Thread is for Olympus Neosplan Objective lens thread size.

26mm x 0.75mm also for Nikon BD 210mm finite objectives, Nikon LU Infinites, and others

M27*0.75 is for Zeiss microscope objective lens thread size.27mm x 0.75mm Zeiss Infinity Microscope Objectives

M32*0.75 is for some Nikon microscope objective lens thread size.32mm x 0.75mm Nikon LU BD Plan series of large industrial objectives

If you need to connect Objective lens(Nikon Leica Zeiss) to Olympus microscope, due to different thread size, then you will need an adapter ring. This is our adpater ring's function.

If you are not sure for the adapter ring size, please tell me your objective lens thread size and microscope brand, then i will give you some advice. thank you very much.

Made of aluminum, anodized black

Note:1 pc x Adapter Ring(objective lens and other accessories are not included.)