Rubber Dub Dub is a level in Bloons 2 and it introduces the Rubber Block. The dart should hit the bloon and land on one of the Tack Bloons. But be careful, as if the dart hits the rubber too hard it will bounce back and hit the metal at the top and if the dart hits the rubber too soft, it will hit the metal wall diverting the two groups of rubber blocks and bloons.