It is a 4 chip set.
The one you are missing from the picture is the first one released which has a picture of the white Harrahs building on the front. The back is the white "play earn learn" logo/slogan design.

They released one each Wednesday of last month (March) as a promotion to people who earned points for casino play in that day. I needed to earn 300 points by 10pm to qualify for them each day each week.

The $5.00 chips have not been released at the cage and cashiers state they "are unable to sell them due to State Gaming regulations that forbid them to sell chips". Some people I talked to only received 2 to 4 chips. so, They appear to be very limited!

I have the whole set and some extras.
I am missing 2 earlier Harrah's chips: Grand Opening, and another blue label on red clay 5 year aniversary date? and would consider trading for them if anyone is interested.

-rich