Battery cases can prolong your iPhone’s life, but by and large, they’re bulky, unattractive and handy only in certain circumstances.

The Boost Case recognizes that and includes a smart feature that can unlock and remove a 1900 mAh battery, Lifehacker reports. So when you need the extra juice, affix the battery. In all other instances, you have a slim protective case for your iPhone. When attached to the case, the battery adds a little more than half an inch of thickness and 48 grams in weight.

Because of its practicality, the case is great for travel and everyday use. The Boost Case is available on Amazon for $79.95.