The Campagnolo cassette lockring holds your casette firmly to the freehub body.
Park Tool FR-5.2 Cassette Lockring Tool - one size
Laser 8197 LTR Cassette Lockring Tool
BBB BTL-12S - Lockout Shimano Cassette Lockring Tool
Unior Cassette Lockring Tool with 12mm Guide
Campagnolo Chorus 11 Speed Ultradrive Cassette 11X 11/27
Park Tool Bbt-5 / Fr-11 - Bottom Bracket Tool / Cassette Lock Ring - Campagnolo
