One of the OTA should be slided to adjust the IPD.
The standard spacing of the EMS-UL allows up to 130mm in the largest diameter of the OTA, mostly the diameter of the dew-shield.

EMS will surprise every new user because it will add or subtract nothing except for erecting the image at the comfortable right-angle viewing.
At the same time, it also surprises the new user for its lightness . It is because no heavy prisms are in it.