DESC: These liners are lap welded for superior strength. Other types of welds are often not as strong and may result in unsightly seams. The virgin vinyl is overlaped, then vulcanized, for a smooth, strong, beautiful surface. This liner is also manufactured with Pro-Grade Marterial made to withstand years of service. This liner will fit most 48" - 52" deep pools. This liner will not work with pools that have a deep end or are deeper than 52". This 20 gauge liner has a 20 year warranty.