The Apple A1978 Series 4 Aluminum Case 16GB Smart Watch in Gray features a sleek and durable design with a 44mm case size made of aluminum. It is compatible with iOS and operates on the Apple Watch OS. This smart watch includes GPS capabilities and has a storage capacity of 16GB, making it ideal for tracking your fitness goals and staying connected on the go. The black fluoroelastomer band provides a comfortable and secure fit for everyday wear.