TropiClean Natural* Flea & Tick Dog Repellent Collar for Large Dogs is used to protect and defend against irritating fleas and ticks. This water-proof collar acts as a full-body pest repellent solution that effectively protects your furry friend. Use with other Natural* Flea & Tick products such as Yard Spray and Max Strength Shampoo for additional pest protection. *Made with natural active ingredients