This is a pack of different electric motors that can be used as loads on trucks and for cranes to lift. The number before the first period is the weight in metric tons and the numbers after that are the width in meters.
The name begins with the type of load, followed by the weight in metric tons. The last is the width.
EM = Electric Motor
43 = weight 43 metric tons
3 = width, 3 m wide
Weight ranges from 43 mt (94,000 lbs) to 82 mt (180000 lbs)