S-Hook Keepers (Pair) - Black. Product Description. This handy rubber keeper provides an extra measure of safety for the safety chain by preventing the S-hook from bouncing out when you're driving on bumpy roads.. Sold in pairs. S-hook not included. WARNING: This product can expose you to chemicals including di(2-ethylhexyl)phthalate (dehp),LEAD which are known to the State of California to cause cancer, birth defects or other reproductive harm, and CADMIUM which is known to the State of California to cause cancer or other reproductive harm. For more information go to P65Warnings.ca.gov.