Pair Coarse Thread to Fine Thread split nut adaptor used to convert older pre-2015 Davey QB pumps, MaxiFlow pumps, Piranha pumps, and others to use the more current fine-thread on Davey QB 'Aus', LX LP & WP, SpaNET XS, Waterway pumps.

Cannot be used on course threads.

Suits thread diameter approx 76mm 
70mm internal sleeve diameter 

•  - measures ~78-79mm OD on pump