This EMS-UL SET wit IPD-Helicoid will offer the IPD range of 60(minimum) to 78mm(maximum) at the “D” of 160mm.(60-73 at the D of 155mm for example)

The total light path in this EMS is 166mm at the IPD of 64mm. The larger the IPD,the shorter is the light path.  But considering the margin of 15mm, the back-focus should be secured about 180mm or longer.