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 is compatible with various SportDOG Brand electronic training collar systems. It can be charged in just two hours, providing up to 40-60 hours of use per charge. The FieldTrainer 425X/SportHunter 825X Add-A-Dog Collar Blaze Orange is a versatile and reliable addition to any dog training setup. With fast shipping, you can get started with your new collar right away.Product Features and Specifications: Model: Sportdog FieldTrainer 425X/SportHunter 825X Add-A-Dog Collar Blaze Orange Weight: N/A Dimensions: N/A Battery Type: Rechargeable lithium-ion Charging Time: 2 hours Battery Life: 40-60 hours per charge Compatibility: Various SportDOG Brand electronic training collar systems