The HE247DPB has a maximum contrast ratio of 40000000:1. That's over two times the contrast ratio of the most frequently found dynamic contrast ratio of 20000000:1. The best contrast ratio of all medium monitors that came out more than two years ago is 100000000:1 and the worst is Mega Contrast.
We think you might also be interested in some of the alternative flatpanel monitors that have a 40000000:1 dynamic contrast ratio currently available including because of it's better review score, the HE247DPB (£94.97), or the HE225DPB (£74.98) both from Hannspree.
If the contrast ratio of this medium monitor is too low for you then you might also want to look at the AOC E2461FW (£122.19) (50000000:1 and higher rated), or the Asus VS228 (£85.60) (50000000:1 and higher rated); or the Asus VS247 (£105.74) (50000000:1 and cheaper).