Zipp: Things to Remember Use with threaded presta valve For use with threaded presta non-removable core tubes Knurled end to keep pump from slipping 3mm extender hex broach in the barrel to guarantee a perfect seal when tightenedSpecifications 27mm extender for Zipp 202 33mm extender for Zipp 303 48mm extender for Zipp 60 /404 72mm extender for Zipp 808 98mm extender for Zipp 1080