Product Description

Pump Lid; Model 90 (2920816000) Discontinued Replaced by Pump Lid (2901116010) http://www.inyopools.com/Products/07501352050130.htm 
and Lock Ring w/ Handles - Lid - 2921116022 http://www.inyopools.com/Products/13801352085117.htm the new lock ring is required with the new style lid. 

THIS IS A ONE PIECE LID WITH FEMALE THREADS. THERE IS AN ALTERNATIVE NOW WHICH REQUIRES 2 DIFFERENT PART NUMBERS. THE FIRST IS THE CLEAR LID WITH NO THREADS. THE SECOND IS A LID LOCK RING WITH FEMALE THREADS, WHICH HOLDS THE LID THESE ARE THE PART NUMBERS 5140-121 LID 5140-122 LID LOCK RING