PVC Pipe adapter

[JackSchmidling]

What does this mean from Home Depot...

1-1/4 in. PVC Sch. 40 MPT x S Male Adapter

I need to go from 1-1/4" PVC to 1" npt, either sex will do.

What is "S"

What size is the pipe thread?

 

[Diehard]

The 1-1/4" end is Male Pipe Thread(MPT).
The other end is socket(or slip).

What type of connection would you prefer on the 1-1/4" side?
And your 1" NPT I assume would be male.

Sounds like you may be looking for this.
https://www.homedepot.com/p/Charlot...ducer-Male-Adapter-PVC-02110-0900HD/203825618

Are you doing water piping or drain piping? As typically drain piping is referred to as DWV(drain, waste & vent). However, don't think it would go down to 1" size for drains.
So you would use a Sch 40 version, which has a higher pressure rating.