The Blagdon \'all-you-need pond lining system\' is a combined pre-packed pond liner and underlay kit for constructing your garden pond. The liner is a 0.5mm PVC liner with a lifetime guarantee, this is complemented by the synthetic underlay which prevents damage to the liner and will never rot. To work out the liner size required: Liner length = maximum length of pond + (2 x maximum depth of pond) + 50cm Liner width = maximum width of pond + (2 x maximum depth of pond) +50cm This pack is suitable for creating a pond approximately 2.4m x 1.7m x 0.55m (LxWxD) which will hold approximately 2280 litres (502 gallons) Actual underlay size 3.9m x 4.4m Actual liner size 3.5m x 4m