Leaf Guard Balloon The Leaf Guard Balloon can be used in both the inline outlet and the pre-fabricated outlet for the storm drains. It is designed to stop the flow of leaves and large granules of dirt flowing down the storm drain and into the 110mm undergound pipe which could cause blockages and expensive problems if the drain needs to be rodded. Price: £2.40 (Excluding VAT at 17.5%) Quantity: