Cannon rotation clamping

I am trying to make a cannon for my game that will rotate using the horizontal and vertical axis, I've tried many types of rotation, and I can get it to rotate but I can't clamp it. How can I clamp both the vertical and horizontal rotation of my cannon? Here's my code

 public Transform cannonHead;
 
     public float rotateSpeed = 100f;
 
     float h;
     float v;
 
     void Update()
     {
         h = Input.GetAxis("Horizontal");
         v = Input.GetAxis("Vertical");
     }
 
     void FixedUpdate()
     {
         cannonHead.Rotate(v * rotateSpeed * Time.fixedDeltaTime, h * rotateSpeed * Time.fixedDeltaTime, 0f, Space.World);
     }