Alle 60, Alle 100, and Alle 300, and the Uria 60, Uria 100, and Uria 300 units are designed for birds that are active at night, or that reside in burrows or cavities where light is not useful for charging batteries.  Unit function can be programmed through a remotely linked base station.

• Weights 4.5g, to 13g (depending on configuration).
• Batteries last for approximately 500, 1000, or 3000 GPS points.
• Rechargeable batteries if units are retrieved.
• Units last for 1-3 years.

The Alle and Uria units require a handheld or station mounted receiver to retrieve data from birds, which can be placed near nests or colonies.