The magnetic top allows the air to be squeezed out easily before the roll top is closed.
D loop at top allows bag to be secured.
Fabric seems relatively durable.
5L 45g, 20L 72g, 30L 83g
30L dry bag was perfect to fit my 40L pack once half emptied for attaching to my packraft. 20L was a good size for sleeping bag and other keep dry essentials inside my pack. 5L good for cooker or small electronics etc.
Really happy with these bags!