A ver que os parecen los productos que oferta esta web y os pongo tb los datos tecnicos que me han enviado. The YellowJacket technology relies on customized ultra-wideband RF components and patent pending techniques to achieve excellent picture quality. The available receiving channels are: 2.370, 2.390, 2.410, 2.413, 2.414, 2.430, 2.432, 2.450, 2.451, 2.468, 2.470, 2.490, 2.510 GHz. These are organized in 4 easy to access frequency groups. See owner's manual. The YellowJacket PRO: Features: 2 audio / video outputs so that you can send the output to both a recording device and a monitor at the same time without an external video splitter/ amplifier--it is built in. The Pro also can receive 2 audio channels from transmitters like the Iftron Stinger Pro, that can transmit 2 audio channels. The YellowJacket Pro also has a special microphone input that allows the user to make and record comments in real time, while the action is happening! The microphone input features a professional grade Automatic Level Control (ALC) amplifier with noise suppression technology to reduce background noise while providing a high quality sound output without distortion from a wide range of input sound volumes. The microphone input is compatible with most lectret, computer type microphones with a 3.5mm audio jack. The YellowJacket STD: Features: Receives one audio channel, has one audio / video output and does not have a microphone input. RF performance is identical to the PRO. Iftron's Stinger and Stinger Pro transmitters put out 27dBm (1/2 watt) and can broadcast on 4 frequencies: 2.414, 2.432, 2.450, 2.468 GHz The Stinger PRO: Features: The PRO transmitter features ultra-wideband video modulator for very sharp video transmission. Stinger Pro also transmits 2 side channels for audio and data. One side channel features an ultra-sensitive microphone input with a broadcast quality Automatic Level Control (ALC) amplifier that can pick up a whisper, yet will not overload from the loudest noise. Stinger Pro comes with a Universal Camera Power Supply (UCPS) that can be programmed to power your miniature camera at either 5V or 12V from any input power source from 6V to 16V DC. The Stinger STD: Features: The STD transmitter has 1 line-level audio input, no microphone amplifier and has no camera power supply. RF performance is identical to the PRO. Please see our website www.iftrontech.com or more technical details and pricing. I have attached a ZIP copy of the operating instructions for you. Availability: YellowJacket receivers are in stock now. Stinger transmitters will be back in stock in about 2 weeks.