All manufacturing defects can be shipped back to the manufacturer at their expense however, since the product is modular they will first send replacement part(s) to resolve any defective part(s).  In this case, the manufacturer will cover the shipping and replacement part(s) cost to correct the defect.  From time-to-time transit damage may occur as a result of their third party logistics provider(s) product handling procedures.  They will resolve the matter in the same fashion as a manufacturer defect.  They will replace the part(s) and ship at their expense.  So you’ll know, returns are very rare.