Things to bring:
1. Admission Slip.
Print two copies for safety: one with your passport, the other inside a secure pocket in your bag.
Student ID may not be accepted, subject to discretion of the test center; thus, passport is safest.
*Note: Students testing at their own school -- for example, TAS -- can use student IDs as long as it's not damaged.
3. 10 2B/HB Pencils.
Typically it's useful to have more than enough, so you'd always have a sharp writing instrument in-hand.
Be sure to use a soft one, so the delicate recycled paper used on the real test will not be ripped.
5. Calculator and extra batteries.
Check here for the full list of allowed calculators fo the SAT.
Note that it cannot make any sound, or the proctor has the right to remove you from the test room.
7. Extra layers of clothing.
Per CollegeBoard regulations, Air Conditioning will be provided by the test center, but sometimes, the AC will not be working best at the beginning of the day; therefore, test takers are recommended to dress with thinner layers first, then stack on layers as needed.