Hair cutter cap and hair cutter with cap

A cap for a hair cutter, comprising:

• a body comprising a main surface arranged to face towards a subject during use;
• and
• a protrusion protruding from the main surface along a first direction perpendicular to the main surface,
• wherein the protrusion comprises a plurality of ribs extending along a second direction perpendicular to the first direction, the plurality of ribs parallel to each other and spaced apart from each other in a third direction perpendicular to the first and second directions wherein the main surface has a length in the third direction that is greater than a width in the second direction;
• wherein each of the plurality of ribs has a length in the second direction greater than a width in the third direction;
• and
• wherein each of the plurality of ribs has a top that is substantially parallel to the main surface
• such that, during use of a hair cutter with the cap attached, the contact area between the hair cutter and the skin is reduced, and the mutual slide between moist skin and the hair cutter is decreased accordingly, without compromising the hair cutting performance.