The standard PSM ships with a Nikon objective (shown here as NIK C60) and an adapter with M25 x 0.75 threads. The MIT adapter is for Mitutoyo objective with M26 x 36 threads/inch (TPI), and the RMS is for many older objectives with Royal Microscope Society threads, 0.800” x 36 TPI. The C mount adapter mates with Edmund Optics objectives and lens tubes with 1.000” c 32 TPI, and the THOR adapter mates with Thorlabs SM1 threads (1.035” x 40 TPI) in their lens tubes.
These last 2 adapters are useful for adding other optics in front of the PSM or using a simple doublet to get a longer working distance objective. The PSM has a 100 mm efl tube lens so a 100 mm efl doublet will give 1:1 magnification. The standard Nikon 10x objective gives 5x magnification with the PSM.
The adapters are held in the PSM by 4 set screws, two on either side of the PSM body. A 2.5 mm hex wrench is used to loosen the M3 set screws.
Disclaimer: All specifications and prices are subject to change.