The perfect strainer for flat roof drains - YouTube
Frost Roof drain assembly - inverted roof with clamp, fixed dome 220mm and 150mm gravel guard, large sump body cast iron vertical outlet size 100mm spigot - 33-0321 by Frost Drainage
DOITOOL Floor Drain Cover Stainless Steel Drain Rooftop Drain Cover Filter Strainer Roof Drain Cap Roof Drain Basket Anti Blocking Line Cap Floor Drain Gutter Strainer Roof Strainer - - Amazon.com
Through wall parapet roof outlet guard 65 x 100 mm, used with an insulation wedge | Polprofili