Euro door handle sets are designed for use on external doors where high-security is needed and a modern style key is desired. The backing plates will have a larger Euro-shaped keyhole cut-out that will fit the euro cylinder (C4 type). These handles require both the "Euro lock body" and the cylinder. The cylinder is available with keyholes on both side of the door, or a keyhole on the outside and a thumb turn on the inside. Internal Mechanisms (Tube Latches & Mortice Locks) to operate this handle set are sold separately.