Please see below to download the manufacturers specification file.
Note that the W56H and RT20 are compatible with the W52P base.
Yealink W60P / W56H
Yealink W52P / W52H Specifications
Yealink RT20 Datasheet.pdfDetailed specifications file (2 pages)
Yealink W56H Datasheet.pdfDetailed specifications file (2 pages)
Yealink W60P Datasheet.pdfDetailed specifications file (3 pages)