Side by side.

Specification	SD-727 SD-727 Quote
Width	1.560"
Height	1.800"
Flange	0.250"
Material	Rubber
Type	Sponge
Durometer	2A4 (sponge grade)
Colour	Black
Mount	Push On
Bulb position	Side
Core	SD-500L Spring Steel

Spec sheets live on each part's page.