INTEX 1.25" to 1.5" Type B Hose Adapters for Pumps & Saltwater System | Set of 2

We have recently purchased a larger filter to replace the filter that came with the original pool (a 15'x48" Intex Easy Set). Unfortunately, the filter did not come with the conversion adapters, so we will need something like this kit. My question is: now that our pool is already set up using the original pump, is i…

The black nipples with no thread on them that stick out of the side of the pool, these just sort of slide on the nipple and sort of compress?

I have the 18 X 48 metal frame pool and It came with a 1500 gph pump so it doesn't sound like I need these adapters. Does anyone know?

Can anyone tell me why these are $27.00 a pair? Almost ordered, got them from Intex for $7.00 a pair.