An impact absorption plate for absorbing impact in the event of a vehicle crash and a method of manufacturing the impact absorption plate includes a base plate and a plurality of bosses. This circuit board has the heaters formed with high precision to reduce their areas. The at least one option apparatus includes a second load driven by the power of the main power supply unit and a second auxiliary power supply that is charged by the commercial power supply when the at least one option apparatus is mounted, while heating the auxiliary heater in conjunction with the first auxiliary power supply. A water pump flows the water through the water circuit. Thus, the manufacture of the power transmission chain 1 is decreased in the number of operation steps, so that the chain may be assembled easily. Because it is water based, no further moisturizing additives are required, and those with sensitive skin, diabetes, allergies or religious beliefs are able to use the product without concern.