Aboveground LinersStandard Unibead Liner Patterns GLI Willow Creek 52′ & 54′ Unibead liner Doctor 20 year warranty3 year full GLI Concord 52′ Unibead liner Doctor 25 year warranty5 year full GLI Boulder River Rock52′ Unibead liner Doctor 20 year limmited warranty GLI MysticAll DepthsRound/Oval/Rectangle20 year limited warranty Trevi Roma52′ Unibead 20 year limmited warrantyOverlap Liner Patterns GLI Boulder River Rock52′ Overlap20 year limmited warranty