A conduit length adjustment device comprising: a. a female body comprising a locking clip opening; b. a male body, movably arranged within the female body; c. a spring, biasing the male body and the female body away from each other in an axial direction; d. a locking clip, arranged within the locking clip opening wherein the locking clip is movable from an open position to a locked position for locking the male body with respect to the female body; characterized in that e. the locking clip is arranged within the locking clip opening such that it cannot be moved to the locked position by accidentally applying pressure or force to the locking clip, wherein f. at least two walls as limitation means protrude from the female body in movement direction of the locking clip and are arranged at the edge of the locking clip opening and wherein the upper sides of the at least two walls then define the outer shape or outer projection line of the female body; wherein g. the locking clip in the open position does not protrude above the outer shape or outer projection line of the female body; and h. the locking clip in its locked position is located below an outer shape or outer projection line of the female body; and i. wherein the walls are arranged on opposite sides (512, 514) of the locking clip opening at a distance smaller than the actuation width of a human finger which is 10 mm to 30 mm and only wide enough to push or move down the locking clip with a flat screwdriver or a similar flat tool; and wherein outer tooth-like latches are located at the locking clip opening, and wherein the locking clip further comprises: j. upwards directed first tooth-like latches which cooperate with the outer tooth-like latches when the locking clip is in the open position, preventing the locking clip from moving upwards out of the locking clip opening; and k. upwards directed second tooth-like latches which cooperate with the outer tooth-like latches when the locking clip is in the open position, for preventing the locking clip from moving to the locked position without application of a sufficient downwards directed force to the locking clip; wherein l. the second tooth-like latches cooperate with the outer tooth-like latches when the locking clip is in the locked position, for preventing the locking clip from moving back to the open position. a. a female body comprising a locking clip opening; b. a male body, movably arranged within the female body; c. a spring, biasing the male body and the female body away from each other in an axial direction; d. a locking clip, arranged within the locking clip opening wherein the locking clip is movable from an open position to a locked position for locking the male body with respect to the female body; characterized in that e. the locking clip is arranged within the locking clip opening such that it cannot be moved to the locked position by accidentally applying pressure or force to the locking clip, wherein f. at least two walls as limitation means protrude from the female body in movement direction of the locking clip and are arranged at the edge of the locking clip opening and wherein the upper sides of the at least two walls then define the outer shape or outer projection line of the female body; wherein g. the locking clip in the open position does not protrude above the outer shape or outer projection line of the female body; and h. the locking clip in its locked position is located below an outer shape or outer projection line of the female body; and i. wherein the walls are arranged on opposite sides (512, 514) of the locking clip opening at a distance smaller than the actuation width of a human finger which is 10 mm to 30 mm and only wide enough to push or move down the locking clip with a flat screwdriver or a similar flat tool; and wherein j. upwards directed first tooth-like latches which cooperate with the outer tooth-like latches when the locking clip is in the open position, preventing the locking clip from moving upwards out of the locking clip opening; and k. upwards directed second tooth-like latches which cooperate with the outer tooth-like latches when the locking clip is in the open position, for preventing the locking clip from moving to the locked position without application of a sufficient downwards directed force to the locking clip; wherein l. the second tooth-like latches cooperate with the outer tooth-like latches when the locking clip is in the locked position, for preventing the locking clip from moving back to the open position.