Downlights come in all shapes and sizes, this range is small and some have cut out sizes that are are small as just 25mm. To allow for the smallest sizes possible, the LED is integrated into the downlight allowing miniature sizes to be achieved, even smaller than an MR11.
One of the key things consider when you're buying miniature downlights is the smaller they are, the less brighter they become. If you want a recessed downlight with a small hole size that is also bright I'd recommend the Integral 4.5W adjustable . It has a 60mm hole size and a light output of 230 lumens.
They are supplied with or without LED drivers, please check the descriptions. Some of them are dimmable and like with most LEDs, they must be dimmed with LED compatible dimmer switches such as the Varilight V-Pro range.
This range of miniature LED downlights is suitable for display lighting in cabinets, book cases etc. Or can even be used as ambient lighting but you would need to fit plenty of them to achieve sufficient lux levels. If you're looking for a miniature track system for displays we now have the Crompton Mini Track lighting system available here.
LED spotlights are surface mounted light fittings (or luminaires) that are mainly used to illuminate objects such as paintings or ornaments. Miniature LED spotlights aren't usually used for accent lighting.