Repeater is crafted from one redstone dust between two redstone torches on a row of three stone blocks. The component has three jobs in any circuit. First, it boosts a signal back to full strength fifteen — vital because raw redstone dust loses one unit of strength per block, dying out after fifteen tiles. Second, it adds a configurable delay of one to four ticks per click, allowing precise sequencing of pistons, doors, and triggers. Third, it locks signal direction: the device only allows current to flow forward through it, blocking any backward feedback.

Right-clicking the device cycles the delay through four positions, indicated by the second torch's distance from the front. A second repeater placed sideways into the input acts as a lock, freezing whatever signal is currently latched — the simplest way to build a memory cell. These three behaviours combined make the component the most-used non-dust component in advanced redstone engineering.