Island Chunk Booster Modules are special items that let you change the buff of an Island Chunk Booster Block on a Progression Island. These blocks are found on Progression Islands and normally give a base buff, but placing a Module on one will replace that default buff with a new, stronger one.

Modules can be added, removed, or swapped at any time for free.
When a Module is applied, the original buff is disabled and your new Module takes effect in that chunk.
Modules are found in Adventures and other tables.

Base Booster Modules

Reduced Crop Breaks
Chance on Fish Catch to not count towards Fish Out
Auto Bot Fuel Reduction
Island EXP Boost (from manual + automatic actions)
Player EXP Booster (/is slayer EXP)
/is slayer DMG Booster (more damage vs. slayer mobs)

Secondary Booster Modules

+1.15x Island EXP Boost
+1 Increased /is skill Contributions
+5% increased chance to receive a Treasure drop
+2.5% increased chance to receive a Seed drop
+10% increased chance to receive a Clue Scroll drop
Chance to receive a Spawner Shard on Mob Kill