The Mouse Blocker is the worlds first ultrasonic mouse deterrent dedicated to automobiles. The Mouse Blocker is a 12 Volt powered device releasing an ultrahigh frequency noise (that sounds like a jackhammer to humans) to deter mice from nesting inside your vehicle. The Mouse Blocker is designed to protect automobiles from clogged or blocked interior areas, which can ultimately result in severe damage to your vehicle. The Mouse Blocker runs exclusively off a vehicle’s 12V battery or anywhere with a 12V power supply so you don't have to worry about dying flashlight batteries or extension cords. The Mouse Blocker installs in your engine compartment and is designed to be stable in this harsh environment. Safe at under high under hood temperatures, stable at well below zero Canadian winters and unaffected by moisture and dampness associated with exterior operation. Stable in areas of heavy vibrations like tractors and mowers and compact enough (about the size of a deck of playing cards) to hide almost anywhere. The Mouseblocker Classic is perfect for Motorcycles, Snowmobiles, Mowers and farm equipment, ATV's and Jetskis.  Many of our RV dealers use multiple Classics spread out throughout the RV or Camper to protect the space. The Mouse Blocker Classic hits at a very powerful 85 decibels. If you are trying to protect your Car or Truck we recommend our MouseBlocker PRO that is over 300 times more powerful than this or any other deterrent sold on Amazon.