Reference: YouTube video
No of units: 30 units (6 units of 5 different colors)
Paper size used : 2.5" x 5" (take a 5" square sheet and cut into half - take 3 square sheets of same color - totally 15 sheets (5 colors) and cut it into half )
Difficulty: easy , easy to assemble and very sturdy model.
Paper used: normal color printer paper
Time: 1.5 to 2 hours
No glue or paper clip used.