Caterpillar-style premium aftermarket tooth retainer or locking component. Part reference 8E5559. Size/application: J550 Retainer. Matching tooth-system size: J550. Matching pin reference: 6Y8558. Secures the replaceable tooth, protector or ripper component to its matching adapter. Brand compatibility: Caterpillar and premium aftermarket systems built to the matching Caterpillar specification. This hardware fits only the specified system and matching dimensions.