Which end should I attack from? That's the biggest question cats have with the Thermo-Crinkle Tunnel (Sage). With built-in noisy walls and both ends open for attack, it'll be any cat's favorite place in the house. The plush interior and super comfy heated floor will be the perfect snoozing spot after all the fun. Uses our safe, effective 4 watt heater. Machine washable. Indoor use only.