---
uid: input-system-step-5-optional
---

# Step 5 current and all (optional)

For convenience, you can quickly access the last used device of a given type, or list all devices of a specific type. To do this, add support for a `current` and for an `all` getter to the API of `MyDevice`.

```CSharp
public class MyDevice : InputDevice, IInputCallbackReceiver
{
    //...

    public static MyDevice current { get; private set; }

    public static IReadOnlyList<MyDevice> all => s_AllMyDevices;
    private static List<MyDevice> s_AllMyDevices = new List<MyDevice>();

    public override void MakeCurrent()
    {
        base.MakeCurrent();
        current = this;
    }

    protected override void OnAdded()
    {
        base.OnAdded();
        s_AllMyDevices.Add(this);
    }

    protected override void OnRemoved()
    {
        base.OnRemoved();
        s_AllMyDevices.Remove(this);
    }
}
```