Fixed-coded remote systems – particularly those using dipswitches to set the code, are very easy to copy or clone. They also offer a very limited number of possible codes. In other words, these systems only provide convenience, with very limited security. MAIN FEATURES: Durable silicone buttons made to last and last Sleek and stylish carbon look. 433Mhz operating frequency. Transmitters with one to four buttons. Transmitter quick and easy to open for battery replacement. Self-learning receivers with one, two and four channels. Receivers incorporate stable narrow band technology. Weatherproof housing for receiver.