Received Oil Gas Mineral Lease to Sign!

I just received an Oil, Gas and Minerial Lease for me to sign. The property that I have rights are in the County of Fresno, CA. I have 16.66 acres and I have been offered 1/6th royalty, $25 per net mineral acre annual rent (Paid 5 years in advance), and 5 year primary term.

Any advise?