Conceal your 510 threaded cartridge with the spring-assisted KeyBD X. Modeled after a key fob so it can discretely and conveniently go with you wherever you go. The new KeyBD X design features softer, more sleek curves with a rubberized finish and a textured grip that all combine to make it super comfortable to hold. The chrome metal accents have been replaced with beautiful and subtle gunmetal to ensure the device is as discrete as it is functional. The button is now also constructed with a rubberized finish and has a larger surface area to make the device even easier to use. On the inside, the updated KeyBD X features a 650 mAh battery which is an increase in capacity of over 85% versus the KeyBD VV. Simply put, less recharging means more enjoyment and ease of use! For the first time in a KeyBD device, it also now includes Pre-Heat functionality and a battery life indicator. This is the best KeyBD ever. Clicking the button 3 times to access variable voltage functionality ensures that it is always easy to adjust the device for low, medium and high power settings.