SafeFamilyLife by SafetyTech Pool Alarm with Remote Receiver Electronic Monitoring System Motion Sensor For In or Above Ground Pool. Alarm Will Sound if Tampered with or Your Child Tries to Remove it Comes with a Remote Receiver Which Can Be Mounted in Your Home Up to 200 feet from the Main Unit Automatically Sounds an Alarm When Children or Pets Fall into Your Unsupervised Pool If the pool alarm doesn't seem to react to swimming objects or doesn't seem to work - This issue can be ususally resolved by installing new batteries and trying again. Please refer to the manual that is sent along with the package. If the issue still seem to persist, please contact the Amazon Customer Support / Seller / Manufacturer for more details