Sizes for 12″ lengths: 3″ through 8″, adjustable from 3″ through 10″ Sizes for 18″ lengths: 9″ through 12″, adjustable from 3″ through 16″ Sizes for 18″ lengths: 14″ through 30″, adjustable from 5″ through 16″
Adjustable lengths telescope onto standard AmeriVent pipe sections.
