Monitor flea infestations year-round! TERRO Refill Glue Boards allow you to always have a fresh one on hand for your TERRO Flea Trap. Fleas leap into the trap where they get stuck fast on a SuperGrabber glue board. The glue boards will also capture other insects that attempt to cross its path. Put in a fresh glue board every two to four weeks, or when the glue board becomes full. To replace, simply insert a new glue board into the trap, glue side up. Then remove the release paper to expose the glue. Finally, dispose of the old glue board. This pack includes three glue board refills.