You’d be forgiven for confusing OtterBox’s new OtterSpot for a stack of restaurant buzzers, those vibrating devices that you hold onto while your takeout is being prepared. But the OtterSpot is more exciting than that. It’s a wireless charging system, and each layer of the OtterSpot is a portable 5,000mAh capacity battery with its own Qi charging coil and support for USB-C wired charging.

The OtterSpot costs $129.99 and it ships with a charging base and one wireless charging battery. Each additional battery costs $69.95, and OtterBox says the 36W base can charge two additional batteries (totaling three OtterSpots) stacked, with a phone on top. An OtterBox spokesperson told The Verge the system can actually handle up to four stackable batteries, but charging speeds are diminished.

Wireless charging is something that more people are interested in, since plenty of popular phone models support Qi charging, like the iPhone XS, Samsung Galaxy S10, Google Pixel 3, LG G8 ThinQ, and others. However, it’s something most people only do at home or at the office, due to the fact that most chargers require a wall adapter to get the fastest charging speeds. OtterSpot aims to solve this by allowing each battery to charge at 10W speeds, if your device supports it.

You can save a lot of money and get much faster charge speeds from a wired USB-C PD portable battery and the right cable. But you’ll miss out on the OtterSpot’s cord-free wireless charging capability, and its slim discus-shaped design that seems easier to fit in a bag than a big rectangular battery.

OtterSpot is now available for purchase at Otterbox.com.