Minecraft wiki entry for Pulse, associated text: When the input turns on, the torch will turn off, allowing both clocks to cycle into a state where the bottom clock will continue to hold the torch off until it's completed one full cycle. The hoppers can hold up to 320 items (X) and the droppers can hold up to 576 items (Y). The duration of the output pulse will be X × (2Y-1) × 0.8 seconds.