The Sportdog FieldTrainer 425X/SportHunter 825X Add-A-Dog Collar Blaze Orange is designed for dogs weighing at least 8 pounds and having neck sizes between 5 and 22 inches. This rechargeable lithium-ion battery-powered collar receiver can be charged in just two hours, providing up to 40-60 hours of use per charge. The Sportdog FieldTrainer 425X/SportHunter 825X Add-A-Dog Collar Blaze Orange is compatible with various SportDOG Brand electronic training collar systems. Fast shipping ensures you get your new collar quickly. This versatile collar receiver can be used as an additional dog collar or to replace a lost or damaged one. Its long contact points and durable design make it suitable for various hunting and training situations.Key Benefits and Features: Weight: 8 pounds Neck size: 5" - 22" Battery type: Rechargeable lithium-ion Charge time: 2 hours Battery life: 40-60 hours per charge Compatibility: SportDOG Brand electronic training collar systems