Campagnolo lockrings, an often discussed and confusing subject, do they come with the cassette? Do they come with the wheel? Do you have to buy them separately? If you purchase any ratio cassette, they supply no lockring. This is because most Campagnolo rear hubs and prebuilt rear wheels should come supplied with a lockring that functions with a 12t or a 13t cassette, some select few wheelsets are not supplied with these though so you may need to purchase one of these lockrings. These lockrings are non-interchangeable, so the 11t lockring won't work with cassettes that start with a 12t or 13t cog….
– Campagnolo 12T Lockring Cassettes & Freewheels – £14.99 (RRP – £)