E40

This is the colour of which the device is mainly composed.

This is the fitting of the lamp that fits into the device.

Colour Rendering Index indicates how correctly a light source reproduces the colours it shines on. The higher the CRI, the more correctly the colours are rendered under the light source.

With a dimmable lighting fixture, you can control the intensity of the light. Usually this is with an external, NOT included dimmer. When in doubt, inquire.