If your return line is just a pipe without threads and no other fitting will fit your pool, the Universal Fitting could be the solution.
For the Universal Fitting to work, the return water flow pipe must be a clear 1 1/2 inches in diameter.
Pooldevil Pro - Only $39.95!
Pooldevil Replacement Socks
Intex Easy Set 3 Inch Fitting
Intex Easy Set Pool 4 Inch Fitting
Aim Flow Fitting - 1 1/2 Inch
Aim Flow Fitting - 2 Inch
External Thread Fitting
Filter Locking Ring
Maxi Pooldevil Replacement Socks