To install the Floorify end profile, you need to leave a clearance of 27 mm. Take into account the width of the upstanding edge of your profile, the width of the profile itself and the 5 mm expansion joint between the rail and the profile.
Calculation:
6 mm (width of upstanding edge of profile) + 16 mm (width of end profile) + 5 mm expansion joint = 27 mm (see drawing)