MMSZ5245BT1G by Onsemi is a Zener diode with 15V nominal reference voltage, 8.5mA test current, and 16 ohm dynamic impedance. It is used in applications requiring precise voltage regulation in a compact SMD package for temperatures ranging from -55 to 150°C.
Vishay Intertechnology's SMBJ18CA is a bidirectional TRANS VOLTAGE SUPPRESSOR DIODE with a max clamping voltage of 29.2 V and a breakdown voltage of 21.05 V. It is surface mountable and commonly used in transient suppression applications.