For a secure liner installation. Throw out those old, worn out coping strips and replace them with new ones. These plastic, non-corrosive clips hold your liner in place on the pool wall before re-installing the top rail. Brand new coping strips will help ensure a firm, proper liner installation. POOL SIZES and NUMBER OF COPING STRIPS NEEDED 15-feet round - (23) Coping Strips Needed, 18-feet round - (28) Coping Strips Needed , 21-feet round - (33) Coping Strips Needed, 24-feet round - (38) Coping Strips Needed, 27-feet - 28-feet round - (44) Coping Strips Needed, 30-feet round - (47) Coping Strips Needed, 33-feet round - (52) Coping Strips Needed, 12-feet by 24-feet oval - (31) Coping Strips Needed, 15-feet by 24-feet oval - (32) Coping Strips Needed, 15-feet by 30-feet oval - (38) Coping Strips Needed, 16-feet by 32-feet oval - (41) Coping Strips Needed, 18-feet by 33-feet oval - (43) Coping Strips Needed