The platform includes the Proximity Beacon API designed to associate content with individual beacons. Other colors for flashing lights or beacons are not allowed. Airborne surveys used radio triangulation beacons, such as Siledus. Rotating lights may be used in lightbars as well as in single beacons. All radio navigation beacons are required to monitor their own output. Abergavenny provides access to the nearby Black Mountains and the Brecon Beacons National Park. LEDs are also used to light some omnidirectional beacons. Wales has three national parks&colon; Snowdonia, Brecon Beacons and Pembrokeshire Coast. The Brecon Beacons (, ) are a mountain range in South Wales. Devonian sandstones (the Old Red Sandstone) from the Brecon Beacons has been used. The latter include WAAS and the U.S. Coast Guard's network of LF marine navigation beacons. The list of active light houses, lighted beacons, etc. NASA and ISRO have also launched experimental satellites carrying K band beacons recently. The newest 406-MHz beacons incorporate GPS receivers. We also collect information through our use of cookies and web beacons.