The TE Connectivity 50428-1 is a silver-plated copper alloy ferrule — the metal sleeve that gets crimped or soldered over the braid or shield of a coaxial or shielded cable before the connector body goes on. It belongs to the 50428 series of accessory ferrules, which are the bits that finish the cable end so the shield termination is solid and the connector body seats correctly. The silver finish on the copper alloy body keeps the contact resistance low where the ferrule meets the shield braid, which matters most in RF or high-frequency signal paths where a poor shield termination bleeds common-mode noise into the signal.
The 50428-1 ships in Bulk packaging — loose ferrules in a bag or box, not tape-and-reel. That is the normal delivery for a crimp ferrule that gets hand-fed into a crimp tool or soldered one at a time on a bench.