I am looking for a short, 1 -2 page charging agreement

I am looking for a short, 1 -2 page charging agreement, I run a planning consultancy business where we have standard terms and conditions which I can share with you. I am looking for a short, maybe 1 to 2 page document to be created which I can send out to clients to pre-authorise up to 5 hours of our time during the course of an application, which I can then bill to them at the end of the project. Any hours over and above this would need further consent from them. We have to be ethical and truthful in our charging, so not all jobs would be billed for 5 hours, some maybe 1 or 2.