R503Pro have R503Pro-UART and R503Pro-USB type, it have 1500 capacity. The LED can be controlled by command.

 
R503Pro Parameters:

·Interface: UART(TTL)/USB
·Voltage: R503Pro-UART: DC 3.3V   R503Pro-USB: DC 5V
·Resolution: 508 DPI
·Fingerprint Capacity: 1500
·Sensing array: 192*192 pixel
·Fingerprint module external size: Diameter 28 (mm)
·Fingerprint module inner size: Diameter 25 (mm) (M25)
·Fingerprint module height: 19 (mm)
·Collection area: Diameter 15.5 (mm)
·Connector: SH1.0-6Pin
·LED Control: YES
·LED Color: RGB

Pin Definition:

Pin    Name    Description
1    Power Supply    R503Pro-UART: DC 3.3V 
2    GND    Signal ground.  Connected to power ground.    
3    TXD    Data output. TTL logical level
4    RXD    Data input. TTL logical level
5    WAKEUP    Finger Detection Signal. Standby-high level, have finger-output low level.
6    3.3VT    Touch induction power supply, DC3—5V