Side by side.

Specification	SD-12636 SD-12636 Quote
Width	1.315"
Height	0.836"
Flange	0.250"
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.