A line-of-sight apparatus locking arrangement for demountably securing a line-of-sight apparatus to the arrangement is provided. The arrangement includes a first and second locking devices, each of which includes a handle member adapted for attachment to a rotation mechanism. The rotation mechanism is coupled to a translation mechanism adapted for, during maneuver of the locking devices, converting rotational motion into translator motion. The translation mechanism includes a pressing portion provided for abutment against an abutment area of the apparatus.