Shown here are the part numbers for the KL03 MCU family. More details on each of these part numbers can be found in the data sheet. The KL03 is offered in two different QFNs (16/24) and a WLCSP version. With the small WLCSP at just 1.6 x 2mm, and the QFNs are not much bigger at 3 x 3mm and 4 x 4mm.