changing constraints of object based on ipad or iphone

In my code to reach the desired effect i can only do it if I change the constraints based on whether the using a iphone or ipad. So i need to create something like if iphone constraints = and then if ipad constraints. I wrote a example of what I needed to do. I just need to change the the last line of the 4 statments controlling the bottom ancor.

     //ipad
     NSLayoutConstraint.activate([
        
        box.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.25),
        box.widthAnchor.constraint(equalTo: view.widthAnchor,multiplier: 0.10),
        box.centerXAnchor.constraint(equalTo: view.centerXAnchor),
        box.centerYAnchor.constraint(equalTo: view.centerYAnchor),

      ])

 //iphone
     NSLayoutConstraint.activate([
        
        box.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.25),
        box.widthAnchor.constraint(equalTo: view.widthAnchor,multiplier: 0.10),
        box.centerXAnchor.constraint(equalTo: view.centerXAnchor),
        box.bottomAnchor.constraint(equalTo: view.centerYAnchor),

      ])