A rolling code transmitter is useful in a security system for providing secure encrypted RF transmission comprising an interleaved trinary bit fixed code and rolling code. The area is opposed to a bottom wall of the first carrying chamber on the lower side in the gravity direction of the first screw member and opposed to the side walls of the first carrying chamber on both lateral sides orthogonal to a rotation axis direction of the first screw member. While the second part interacts with the first part, the antenna is tuned to a third frequency band.