RuiLing 2-Pack PC Motherboard Mini Plug Speaker Desktop Computer Case DIY Internal BIOS Beep Alarm Buzzer : Amazon.ca: Electronics
Amazon.co.jp: Audio Fan PC Motherboard Buzzer, BEEP Buzzer, Beep, Speaker, DIY PC, PC Assembly, BIOS Alarm, Problem Check, Power Checking, POST Checking, Total Length: Approx. 2.0 inches (5 cm) (including terminal speakers)
Amazon.com: Gikfun PC Motherboard Internal Piezo Speaker BIOS Alarm Buzzer for Arduino Computer Case DIY (Pack of 10) EK1795 : Electronics
How to Connect a PC Speaker to Your Motherboard - YouTube