Speaker spacers make car audio installation a snap.  They give you the extra depth you need to mount deeper aftermarket speakers.  They can be used in conjunction with speaker adapters.  Speaker spacers are available in both 1/8" and 1/4" thickness.  Use alone or stack them for just the right amount of clearance.  Each kit includes one pair of spacers.  In cases where you can not use speaker spacers due to grill clearance issues, consider installing smaller aftermarket speakers using speaker adapters.