The slamm internal semi sealed headset consists of a cup which is integrated into the head tube so it sits flushthe bearings sit inside the head tube and sealed in place to protect them from dirt and dust supplied with all of the required covers and nuts1 18 size standard across most popular scootersinternal cup semi sealed bearingssmoother and quieter use than unsealed headsetsremoval of fork is easier and cleanerdust seals for reduced maintenancefull steel constructionthis headset is suit