The original Liquidator saddle fitting is not a great piece of hardware, to say the least.
It has two major flaws:
1. The clamp has a shoddy construction. If you have to loosen and retighten it a few times it gets ruined beyond repair and you can’t tighten it.

2. The seal is made by a flat disc pushing an O-ring disc against a curved pipe (a 1 1/2” PVC pipe.)
In order to get a leak-free seal you need lots of luck.

Because of these two reasons the Liquidator’s original saddle fitting was reported to leak. Mine did too.

HASA is not a hardware oriented company (they sell bleach) but Hayward is.
I installed Hayward’s saddle fitting made for their chlorinator .
See for instance here.

It’s available on line and in pool supply stores.
Unlike HASA’s, the disc is curved to match the pipe’s curvature and the clamp is made a lot better.
The unit comes with about 2 feet of black plastic tubing (PE?) that you want to use for the fitting. You can connect it to your flexible vinyl or whatever with ¼” barb tubing fitting available at Low’s. Don’t use brass!
Before I attached the saddle fitting I wrapped around the 1 1/2" PVC pipe a few wraps of Teflon tape and punctured the 3/8” hole. Unlike HASA’s fitting this was a one shot deal: It sealed right away with no leaks!