Side by side.

Specification	DU-204 DU-204 Quote
Width	1.324"
Height	0.607"
Flange	0.600"
Material	Rubber
Type	Sponge
Durometer	70 Shore A
Colour	Black
Mount	Push On
Bulb position	Side
Core	1.7in Wire

Spec sheets live on each part's page.