Dogtra ARC HANDSFREE Plus Boost and Lock, Remote Dog Training E-CollarFeatures: NEW BOOST & LOCK FEATURES: Enhance your training experience with the superior Boost button. The constant correction with a customizable Boost button allows for instant level increases to immediately recall you dog. Go from training mode to obedience mode easily by setting your own custom Boost to jump to your enhanced training level seamlessly. The newly introduced Safety Level Lock prevents unwanted or accidental level changes for an active