DNB D90II’s Rockbreaker One of DM Breaker’s most popular and versatile models, the DNB D90II’s rockbreaker was manufactured to suit machines weighing between 18-30 tonne. The DNB D90II’s is bursting with the power of 4400 joules in order to give it’s user optimum advantage on site. Powerful, reliable and extremely efficient the D90II’s rockbreaker makes light work of the toughest rock.