The High End Systems Dataflash AF1000 strobes were recently replaced with Atomic Strobes. Today, strobe synchronization is often used to synchronize all strobes in a uniform flash pattern. These may be motorised rotating beacons, xenon strobes, or arrays of LEDs. Stack lights typically use incandescent, LED or xenon-type strobes as their illumination source. The lights can be LED, or halogen, or sometimes Xenon strobes. In around 70s even smaller studios got access to flash lights or strobes. Either electronic flash "strobes" or incandescent "hot lights" can be used. Depending upon the state, police vehicles may have revolving lights, strobes or light bars. The bikes are provided with two-way radios, strobes and sirens and are generally painted white. They have also been used in photography as a critical part of flashes (strobes). Unlike common white strobes, these strobes are specified not to flash simultaneously. Several manufacturers have also developed medium-intensity white strobes based on LED technology to replace xenon. System Sensor discontinued most of the wall or ceiling mount horn strobes. White strobes (that flash round the clock) may also be used in urban areas.