LED lighting modules provide modern and energy-efficient lighting solutions - from cool or warm white to a choice of colours, principally red, green, blue and yellow. Coloured LEDs can be used as illumination for advertisements, for decorations or to create attractive displays, while certain types of LED module are designed to cycle through three colours (RGB), and white. These are also referred to as RGBW LEDs. Additionally, leading LED lighting manufacturers such as Barthelme and Sloan produce DC lighting LED strips in lengths of up to 10 metres. These require a 12 or 24 volt DC supply from a LED driver. Alternatively, AC LED lighting strips are designed for convenient connection to mains supply voltages. An increasingly popular and very contemporary choice of lighting system, LEDs can be mounted in architectural recesses, around or behind architraves, as well as in cabinets and displays using brackets, fixing clips and linear connector accessories. Other LED fixings include special clamping sleeves, light guides and purpose-designed tube sets. Finally, dimmer controls allow control of illumination levels, with flexible power supply connection cables featuring DC sockets or four-point plugs.