Good morning, I installed this ceiling once before and each box had clips and #1 phillips screws and a tip in it .I would not recomend brad nails ,I think they would blast right through.If I remember correctly(only about a 30% chance

)This is made of paticle bourd with a woodgrain laminate on the face.Also I had to fir down the cieling with 1/2" strips so material can breath-not necesary if applied over framing.My instal was about 6 years ago and so maybe prodect has changed. I would double check and call arstrong directly to make sure clips are included and i would definatley use them.
Good luck ,Steve