AWA251, SG638/SG639.

Frames

Ag 639: extruded aluminium frame, horizontal extruded aluminium rain-protection fins
SG 639: galvanised steel frame and fixed rain-protection fins
Fin spacing 75 mm
Inner part features a square protective screen 12 x 12 made of Ø 1.2 mm galvanised steel wire
AG 639: rough aluminium finish
SG 639: rough galvanised steel finish
Visible screw attachment in frame and mounting frame F11