21d. Bracket with a concrete base in plastic
Concrete brackets are made of 2 mm steel sheet.
Item no. 20 is intended to be concrete-immersed.
Item no. 21 is intended to be glued on a flat concrete roof.
Item no. 21c is a plastic bracket with a concrete weight.
Concrete brackets are intended to mount a lightning line
(anair terminal) on a flat roof. Lightning wire diameter: Ř 6 to Ř 8