What size gap is there between the heat pipes and motherboard? (for small components to pass under)

As part of the cooler assembly, the heat pipes will pass over the motherboard to reach the side panel (heat sink). This means there can not be any tall components between the CPU and heat sink side of the case, however, there is an allowance for low-profile components on the motherboard. The actual gap is approximately 12mm but we suggest that any component under the heat pipe be 10mm or less.