Pipe

 is the thirty-ninth level of More Bloons.

Completion
To complete this level, pop the Triple Dart Bloon, then use the triple darts by aiming for the top with high power, which will pop some of the bloons on the left and on the right. As an added bonus, you can pop bloons by using a dart for each side.

Trivia

 * The Metal Blocks do not entirely form a pipe, but the "function" does work like one.