WHAT IS A NANOBLOCK Amazingly small micro-sized building blocks - the smallest block measures 4mm x 4mm Double ridged backing system makes it easy to clip and unclip Create precise and detailed models Designed by Kawada Company in Japan Over 150 pieces Difficulty: 2 (1 = easiest) With over 150 pieces in each set the average builder takes 30-90 minutes to complete. Includes detailed colour instructions. Collect them all and start your own nano-sized collection.