If you have any questions. durable amplifier rf tools vhf uhf 1-1000mhz 15v 2.5w hf black broadband. Also, the each additional item means. Made of high quality materials, durable and practical Broadband RF small power amplifier, suitable for all types of radio transmission, such as short-wave FM wireless remote control, FM radio station transmission, amateur radio 135-175MHz, 380-470MHz walkie-talkie, etc.