See H3 Image and H4 Image below in sources and related links.
Halogen H4 55 Watts bulb.
they are H4
h4
The lenght of a H4 HID Bulb is about 4 cm from the tip of the bulb to the en of the bulb where it enters the docking plate
The H in H4 when thinking about a lamp would mean a halogen headlamp. So when stocks people are looking for specific bulbs for their customers they should know to look in the car head lamp section of the store when asked for a bulb starting with the letter "H".
Yup they sure do 9003/ h4 fits a 94 civic
H4
The Aygo uses a H4 type of bulb
9003 or H4, same bulb.
H4
H4