Mechanism of Evolution – Natural Selection

Natural selection where more individuals acquired specific character value other than the mean character value, leads to:

In a species, the weight of newborn ranges from 2 to 5 kg. 97% of the newborn with an average weight between 3 to 3.3 kg survive whereas 99% of the infants born with weights from 2 to 2.5 kg or 4.5 to 5 kg die. Which type of selection process is taking place?