1N5221B-1 thru 1N5281B-1 Available on commercial .
1N5278B - SILICON ZENER DIODES
1N5278BUR-1 - METALLURGICALLY BONDED GLASS SURFACE MOUNT 500mW ZENERS
1N5278B-1 - ZENER DIODES
1N5278B - Zener Diodes
1N5278B - SILICON PLANAR ZENER DIODES