When plugging in the FTDI adpater, it get's registered as ttyUSB but shortly
afterwards it gets deregistered and reregistered as input device:

udevadm monitor 
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[4096.004758] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2
(usb)
KERNEL[4096.007131] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0 (usb)
KERNEL[4096.007175] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0 (usb-serial)
KERNEL[4096.007883] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0/tty/ttyUSB0
(tty)
UDEV  [4096.526145] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2
(usb)
UDEV  [4096.531416] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0 (usb)
UDEV  [4096.532623] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0 (usb-serial)
UDEV  [4096.538064] add     
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0/tty/ttyUSB0
(tty)
KERNEL[4096.668041] remove  
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0/tty/ttyUSB0
(tty)
KERNEL[4096.668075] remove  
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0 (usb-serial)
UDEV  [4096.670253] remove  
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0/tty/ttyUSB0
(tty)
UDEV  [4096.671010] remove  
/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/ttyUSB0 (usb-serial)
KERNEL[4100.679481] add      /devices/virtual/input/input38 (input)
KERNEL[4100.679612] add      /devices/virtual/input/input38/event20 (input)
UDEV  [4100.681392] add      /devices/virtual/input/input38 (input)
UDEV  [4100.714831] add      /devices/virtual/input/input38/event20 (input)


lsusb
Bus 001 Device 018: ID 0403:6001 Future Technology Devices International, Ltd
FT232 Serial (UART) IC


dmesg
[ 4330.254760] usb 1-1.2: new full-speed USB device number 19 using ehci-pci
[ 4330.371475] usb 1-1.2: New USB device found, idVendor=0403, idProduct=6001
[ 4330.371480] usb 1-1.2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 4330.371484] usb 1-1.2: Product: FT232R USB UART
[ 4330.371486] usb 1-1.2: Manufacturer: FTDI
[ 4330.371488] usb 1-1.2: SerialNumber: A50285BI
[ 4330.374746] ftdi_sio 1-1.2:1.0: FTDI USB Serial Device converter detected
[ 4330.374826] usb 1-1.2: Detected FT232RL
[ 4330.375406] usb 1-1.2: FTDI USB Serial Device converter now attached to
ttyUSB0
[ 4331.045927] usb 1-1.2: usbfs: interface 0 claimed by ftdi_sio while 'brltty'
sets config #1
[ 4331.046819] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now
disconnected from ttyUSB0
[ 4331.046845] ftdi_sio 1-1.2:1.0: device disconnected