Haz says: Extra box to add for a two dog configuration or a double box setup on a single dog. I love how small and low profile this collar is. Whether in single or double configuration the ARC is probably the lowest profile collar on the market that does not sacrifice performance or a reasonable price price point. Pictures do not do justice to how small this unit is.

Replacement or additional receiver for Dogtra ARC, with an ORANGE strap. Package Contents: Receiver with an ORANGE strap, One 5-5 splitter cable

FEATURES
Receiver with extra charging cable ONLY
3/4-Mile Range
Non-Stimulating Pager Vibration
Low to Medium Power Stimulation
For Dogs as Small as 15 lbs.