Open Electronic Sentry Safe in Seconds with Rare Earth Magnet. To purhcase the same Rare Earth Magnet in the video go to Mr. Locksmith Training. Recommended by Terry Whin-Yates. This is the same magnet that Terry Whin-Yates uses to open electronic Sentry Safe’s in seconds! Dimensions: 3″ dia. x 1″ thick Tolerance”>Tolerances: ±0.004″ x ±0.004″ Material: […]