Introduced in 2011 the Blagdon Ultimate Pond Lining System has proven to be a popular choice. The lining system consists of a top quality PVC pond liner along with underlay of matching size with 20cm overlap.This liner system carries a Lifetime Guarantee from the manufacturer.The liner in this set is 3.5m x 3.0m 11'6 x 10' and the pond liner underlay included is sized 3.9m x 3.4m 12' 8 x 11' 3.