The front bumper shall be of heavy duty steel channel, or equivalent, at least 3/16-inch thickness and not less than a 9-inch face, painted black, and shall extend around the outer edges of the fender. Bumper and bumper supports shall be of sufficient strength to permit towing or pushing by another vehicle without damage. The front bumper shall be furnished by the manufacturer. The rear bumper shall be of 3/16-inch pressed steel channel, or equivalent, and shall have not less than a 9-inch face. It shall wrap around the back corners of the bus and shall extend forward at least 12 inches measured from the rearmost point of the body at the floor line. The rear bumper shall be furnished by the manufacturer and shall be attached directly to the frame with the following provisions: Ease in removal; Prevent hitching to or riding on it; Braced to develop the full strength of the bumper section against side or rear impact; and Permit bus to be pushed by another vehicle without permanent distortion. The rear bumper shall extend beyond the rearmost part of the body surface at least 1 inch, measured at the floor line. Only bumpers approved by the Administration may be used. Tow eyes or hooks may be furnished front and rear and attached so as not to project beyond the front or rear bumpers. Tow eyes or hooks attached to the frame (chassis) shall be furnished by the chassis manufacturer.