The limit is 2 rewards per customer. At Staples, you cannot use rewards to pay for rewards items and get the full amount back (at Office Max, you can). Coupons will also reduce your reward amount.
Anyway, here's what's included:
16 pk. AA or AAA Duracell batteries $10.99
500 sheet ream of Staples paper $6.99
Staples desk pad calendar 22x17" $5.00
These items all will get you 100% of the purchase price back in Staples rewards through Saturday!