only just(The aperture through which the heater blade extends may be dimensioned tightly, at least for a portion of the aperture, so that the heater blade only just passes through the aperture. Мирослав9999)
rightly(For example, the spacer can have an outer depth which corresponds to the inner depth of the box portion such that the spacer rightly fits into the box portion and is kept in place for example by friction between the spacer and the box walls. Мирослав9999)
