A locking system comprising: a round, oblong lock bar (7, 62, 72) having a number of grooves (10, 29, 63, 73) for receiving locking balls, said bar grooves (10, 29, 63, 73) extending all the way round the lock bar (7, 62, 72); a lock cylinder (11, 61, 71) with an outer tube, an inner tube, and a number of locking balls; wherein the inner tube is placed inside the outer tube and has an oblong opening for receiving a part of the lock bar (7, 62, 72) with grooves (10, 29, 63, 73), said inner tube having a number of through-going bores, which bores are positioned so to face corresponding grooves (10, 29, 63, 73) on the lock bar (7, 62, 72) when the lock bar (7, 62, 72) is placed in the inner tube; wherein the inner tube can rotate between a first and a second position relative to the outer tube corresponding to open and locked position of the locking system; wherein the locking balls are placed in the bores of the inner tube; wherein the outer tube has a number of grooves for receiving the locking balls, which outer tube grooves are positioned and formed so that when the inner tube is in the first position relative to the outer tube, which corresponds to an open locking system, then the locking balls can be stored partly in the grooves of the outer tube and partly in the bores of the inner tube without reaching into the opening of the inner tube facing the lock bar (7, 62, 72), and when the inner tube is rotated a certain number of degrees to reach the second position relative to the outer tube, which corresponds to a locked locking system, then the locking balls are pushed totally or partly out from the grooves of the outer tube, so that the locking balls are stored partly in the bores of the inner tube and partly in the grooves (10, 29, 63, 73) of the lock bar (7, 62, 72), whereby the lock bar (7, 62, 72) is securely locked to the inner tube, while at the same time the lock bar (7, 62, 72) and the inner tube can rotate relative to each other; characterised in that the bores of the inner tube are formed so that the locking balls only partly can reach through the bores and the opening of the inner tube facing the lock bar (7, 62, 72), and in that the outer tube has a number of through-going bores for entering the locking balls into the bores of the inner tube. a round, oblong lock bar (7, 62, 72) having a number of grooves (10, 29, 63, 73) for receiving locking balls, said bar grooves (10, 29, 63, 73) extending all the way round the lock bar (7, 62, 72); a lock cylinder (11, 61, 71) with an outer tube, an inner tube, and a number of locking balls; wherein the inner tube is placed inside the outer tube and has an oblong opening for receiving a part of the lock bar (7, 62, 72) with grooves (10, 29, 63, 73), said inner tube having a number of through-going bores, which bores are positioned so to face corresponding grooves (10, 29, 63, 73) on the lock bar (7, 62, 72) when the lock bar (7, 62, 72) is placed in the inner tube; wherein the inner tube can rotate between a first and a second position relative to the outer tube corresponding to open and locked position of the locking system; wherein the locking balls are placed in the bores of the inner tube; wherein the outer tube has a number of grooves for receiving the locking balls, which outer tube grooves are positioned and formed so that when the inner tube is in the first position relative to the outer tube, which corresponds to an open locking system, then the locking balls can be stored partly in the grooves of the outer tube and partly in the bores of the inner tube without reaching into the opening of the inner tube facing the lock bar (7, 62, 72), and when the inner tube is rotated a certain number of degrees to reach the second position relative to the outer tube, which corresponds to a locked locking system, then the locking balls are pushed totally or partly out from the grooves of the outer tube, so that the locking balls are stored partly in the bores of the inner tube and partly in the grooves (10, 29, 63, 73) of the lock bar (7, 62, 72), whereby the lock bar (7, 62, 72) is securely locked to the inner tube, while at the same time the lock bar (7, 62, 72) and the inner tube can rotate relative to each other; characterised in that the bores of the inner tube are formed so that the locking balls only partly can reach through the bores and the opening of the inner tube facing the lock bar (7, 62, 72), and in that the outer tube has a number of through-going bores for entering the locking balls into the bores of the inner tube.