This official F1® Model Block measures 223mm x 65mm x 50mm with a consistent weight of 112grams and contains a pre-drilled hole for the CO2 cartridge. This pack contains 10 model blocks.This will be the only material accepted at the F1 in Schools World Finals commencing in 2015. This new block is grain free, has a consistent weight and density, machines very well and is easy to paint.