The Trevi 1218OV-LUC-UB GLI 12' x 18' x 52" Oval Lucia Above Ground Unibead Vinyl Pool Liner uses UV-resistant vinyl to reduce sun damage and provide superior performance, year after year. All Trevi vinyl liners are computer-designed and manufactured by the brand to exacting standards, ensuring a precise fit. In addition, they use the very latest assembly technology, which sets their products apart from the competition.