In summary, the Swing Lock series from Hirose has a double locking system; positive lock and friction lock. There is a clear tactile click with the positive lock. The positive lock structure provides secure locking to prevent accidental plug release due to stresses or force applied to the cable. The DF57H, DF59, and the DF61 are all UL and CSA approved, and RoHS compliant. Several pin counts are offered in the DF57H and DF59 series. DF61 is offered in two position only.