The Dayspring unit features four temperature settings 
which allows you to adjust the voltage (3.0v/3.4v/3.7v/ 4.0v) within a particular range to suit your personal preference. 
And it has a pre-heat feature(1.8v) to help soften your material, and help get the oils flowing easily. Vape like HipHop.
500mAh Li-Ion Battery 4 Temperature Settings Preheat Function Single Button Operate Magnetic Connection.