There are many purposes for extension springs in our everyday world. From being in our cars that drive us around every day, to the farm machinery that produces our food. Extension springs come in all shapes and sizes with an array of loops and eyes to fasten onto both ends, requiring the need for an extension in some form. Long tension springs used in automotive, instrument, electrical equipment, household appliances, furniture, mechanical equipment, daily living equipment, electronic sports equipment, light industry products, sanitation machinery.