Circular saws have one blade mounted right on the axle of the engine. The saw has a voltage of 36 volts and has a somewhat modest weight of 2.8 kg.
From Data Powertools
HiKOKI CD3605DA/J3Z18/36v 125mm Brushless Metal Cutting Circular Saw Body Only
ITS
Hikoki CD3605DAJ3Z 36V Multivolt Brushless Metal Cutting Saw - Body