Usually it is folded and stored in the buckle part of the driver, but it automatically stretches according to the wearer's body shape. It can release the transformation by the Sengoku Driver. By lowering the blade, the set Lockseed opens, and it exerts its effect.
It has enough strength to withstand power released and also plays a role as a connector for connection that exchanges energy between a Lockseed and the Sengoku Driver.
When releasing the power of Lockseed, it plays the role of a safety device to prevent power runaway.
Lock On Arm ( ロックオンアーム, Rokku On Āmu) is the arm part fixing the Lockseed.A Sengoku Driver consists of the following parts:
