The ProScale LC-300 comes calibrated and ready to use with 2 AAA batteries. The blue backlit display makes using this ProScale digital scale in your reptile room easy, especially in low light settings. Use the tare function when using a container when weighing your geckos, lizards, snakes, or other reptile pets for an accurate weight down to .1 gram! The VibraKill® technology will keep the reading accurate and stable when weighing your animals that might not stay still enough for other scales to give such a precise measurement as the LC-300. This scale is small enough to fit in your pocket and is equipped with a protective cover to keep it safe and stay calibrated longer. The protective cover can also be used as an expansion tray if you need a larger surface to weigh stuff on - just tare the cover and it's ready to go!