AM Roof drain (Alkorplan, Light Grey) 110mm, 110mm/630mm: For Alkorplan roofing. AM-50 and AM-75 roof drains can be used in either a siphonic system or a conventional system. CM Roof drain 75mm, 110mm: For bitumen felt roofing. The 150 mm wide flange should be installed between two felt layers. AM Roof drain Bitumen 75mm, 110mm, 110/630mm, 160mm: For all types of multiple and single-ply bitumen felt roofing. AM-50 and AM-75 roof drains can be used in either a siphonic system or a conventional system. AM Roof drain (Protan, Light Grey) 160mm: For Protan roofing. AM-50 and AM-75 roof drains can be used in either a siphonic system or a conventional system.