The Pixy2 CMUcam w/ Cable + Mounting Hardware kit comes with the following parts. Make sure you have everything:

(1) - Pixy2 Camera with ribbon cable (in camera box; #30027)
(1) - Screw, #4-40 x 3/8" panhead (#700-00002)
(4) - Screw, #4-40 x 1/4", panhead (#700-00028)
(4) - Nut, #4-40 (#700-00003)
(1) - Locknut, #4-40, 1/4" (#700-00024)
(10 wires) - Jumper wires, MF, 100 mm (#800-00063)

From your ActivityBot 360° kit you will also need a Parallax screwdriver (#700-00064) or other #1 Philips screwdriver, and the Parallax Combination Wrench (#713-00007) or other #4 hex wrench.