considering the lack of conformity of the hammer heads delivered by the seller with the provisions of contract, which has constitute a fundamental breach, the buyer shall have the right to require the seller to provide substitute
goods complying with the requirements of the contract. It is unnecessary to further discuss the actual or main cause for the equipment is break down in such case. In addition, the materials and evidence submitted by the seller cannot convince the hammer heads in conformity with the contract has been installed on the equipment.