(3) Any snap or any other hard protrusion fixed onto the surface  of the helmet body is sufficiently small or has an easily  removable structure so as not to obstruct the slipperiness of the  helmet body.  3 (1) The helmet has a structure that fits the wearer's head  well, and does not pose a risk of hurting the head.  (2) The helmet has been well assembled, and has no scratch,  chip, crack, burr, etc. that affects its use.  (3) The helmet has a sufficient horizontal and vertical view.  (4) The helmet includes the helmet body, an impact absorbing  liner, and a holding device. The holding device must not have a  chin cup attached thereto.  (5) The helmet has a structure that does not substantially  decrease hearing.  4 The mass of the helmet is appropriate so that it does not  strain the wearer's neck.  5 When an impact absorption test is conducted, the maximum  impact acceleration of the helmet is no more than 2,940 meters  per second per second and the duration of the acceleration of  1,470 meters per second per second or more is no more than 6  milliseconds (in the case of Helmets for Mopeds, etc., no more  than 4 milliseconds).  6 When a penetration resistance test is conducted, the tip of the  striker does not contact the dummy head used for the test.  7 When a strength test of the supporting device is conducted,  the dynamic elongation is no more than 35 millimeters and the  residual elongation is no more 25 millimeters, and the helmet is  easily removable from the dummy head after the test.  8 When a roll-off test is conducted, the helmet does not come off  the dummy's head.  9 (1) The helmet indicates the name of the Notifying Enterprise  in such a manner whereby it does not fade easily; provided,  however, that an abbreviated name or a mark for which the  approval of the Minister of Economy, Trade and Industry has  been obtained or a Registered Trademark which has been  notified to the Minister of Economy, Trade and Industry may be  indicated in lieu of the name of the Notifying Enterprise.  (2) If the helmet is only to be used for motorcycles with a total  emission of 0.125 liters or less or for mopeds, such fact is  appropriately indicated in such a manner whereby it does not  fade easily.  (3) Precautions for use that will be necessary for ensuring safe  use are appropriately indicated in such a manner whereby it  does not fade easily.  3. Beds for  Babies and  Infants  1 The bed has no crack, burr, or splinter that could hurt the  user's hand or foot.  2 (1) Each part of the bed can be securely assembled without  becoming loose.  (2) Movable parts of the bed can be moved smoothly and  securely.  31 