MR16 LEDs operate of 12V, this can either be 12V AC (alternating current) or 12V DC (direct current). If the voltage is AC, they are designed to work with existing low voltage halogen transformers. If they are DC you'll need an extra LED driver. An LED driver converts the mains voltage AC input into a 12V DC output.
The Philips range of MR16 LEDs we offer below operate on AC meaning you can easily swap them over for your inefficient halogens.
MR11 LEDs are smaller than MR16 meaning they are not as bright but allow them to be fitted into smaller downlights. This allows for smaller, less obtrusive holes to be cut into a ceiling. At present MR11 LED bulbs are not dimmable. We currently offer two types; Philips and Megaman, both are high quality and are a longer lasting alternative to halogen.
If you're looking for a smaller style of LED downlight, check out our EcoLED ZEP0.5 which has a cut out size of just 42mm. It can also be dimmed by selecting a dimmable LED driver.