Powerlifting records in most federations can be set by adding just 1/2 a kilo on the existing record. To do that, you need the "chips" as they are called, small plates that allow you to add any 1/2 kilo increment to the bar, .5, 1kg, 1.5 kg or 2 kg.
This requires one pair of 250 gram plates, and two pairs of 500 gram plates. This set includes that.