The Challenge Slider dog puzzle from Nina Ottosson by Outward Hound is an advanced level 3 game designed for pups who have mastered levels 1-2. This dog toy will promote the mental wellbeing of your dog by keeping them active and engaged while sniffing, nudging, and pawing for hidden treats! A sliding tray pulls out from underneath with 24 compartments that can hold up to 1 cup of food total. Slide the tray back in and place on the floor in front of your pup. Watch them investigate and try to figure out the puzzle on their own or help them with a bit of encouragement to show them how it works by sliding the top pieces around and showing the hidden treats.