SG-400: 8-inch diameter / 324 cm
2 area
(National Weather Service); no heater
SG-410: 8-inch diameter / 324 cm
2 area
(National Weather Service); heater
SG-420: 6.3-inch diameter / 200 cm
2 area
(World Meteorological Organization); no heater
SG-430: 6.3-inch diameter / 200 cm
2 area
(World Meteorological Organization); heater