A 4 in 1 transition strip is the swiss army knife type of transition strip with interchangeable parts that work for different types of floors.
Transition strip from laminate to carpet.
A typical 4 in 1 transition includes a metal channel for mounting the system with a t molding which fits into the channel and is used alone if you are joining floors that are the same height.
I had to add ne.
When i start working on this project a carpet was already installed.
Cut the end cap using a saw to the correct length of the doorway that separates the laminate floor from the carpeted floor.
This video is about how to install laminate floor transition to carpet.