Avent is the biggest size for boiling some different brands of bottles. I am using the biggest size of Dr. Brown bottles with Avent Steamer.
I have checked & located a period time for different steamers.
Before buying the Avent, all my friends suggest to use traditional cooking 'Ladder'-'Bowl'.
Anyway, I have using this Avent for more than one year & also very good / convenience to use it.