Small converter that fulfills its purpose very well, namely transmitting sound on a TV not equipped amp optical input through optical cable (not supplied). There is a small transformer and with the operation lamp is not too powerful, it does not shine in the dark ... or we can hide that witness with a black adhesive, no worries. Attention however to equip yourself with a good optical cable protected from static or "armored" electricity, I have bought mine on Amazon (Amazon is a cable), and the cable regularly issued very unpleasant slamming .. . I then ended up changing it and from the converter works great ... If you have a concern of his with this type of device, consider First of another cable to test your installation before venturing to change the converter! a star less because I do not like the devices that we have to keep constantly connected to the sector even if it does not consume much! and do not take optical cable with Amazon ...