John Deere-style premium aftermarket tooth retainer or locking component. Part reference TK4LI. Size/application: Retainer TK400. Matching tooth-system size: John Deere TK400. Matching pin reference: TK400PI. Secures the replaceable tooth, protector or ripper component to its matching adapter. Brand compatibility: John Deere and premium aftermarket systems built to the matching John Deere specification. This hardware fits only the specified system and matching dimensions.