According to the U.S. site, the 05 appears to be 5sm visibility. Go here:
http://adds.aviationweather.gov/metars/index.php
and enter the ICAO code and hit the TRANSLATE button on the right.
8km=5sm
METAR text: WIII 101230Z 02004KT 350V050 8000 (05) FEW023 SCT120 28/24 Q1010 RMK NIL NOSIG Conditions at: WIII (SOEKARNO-HATTA I, ID) observed 1230 UTC 10 October 2007
Temperature: 28.0°C (82°F)
Dewpoint: 24.0°C (75°F) [RH = 79%]
Pressure (altimeter): 29.82 inches Hg (1010.0 mb)
Winds: from the NNE (20 degrees) at 5 MPH (4 knots; 2.1 m/s)
Visibility: 5 miles (8 km)
Ceiling: at least 12,000 feet AGL
Clouds: few clouds at 2300 feet AGL
scattered clouds at 12000 feet AGL
Weather: no significant weather observed at this time