Name of power tool which joins copper pipes without soldering?

[Pamela]

What is the name of the hand power tool which joins copper water pipes without soldering? Is the correct term a "press tool"?

The plumber who fitted an expansion tank to my central heating system used one of these and thought highly of them although said they were quite expensive.

[Andy Burns]

"press tool" or "copper press-fit tool"

yes around a grand for the battery ones, more for a wider variety of jaws sizes.

[Pamela]

Thank you.