Side by side.

Specification	SD-750-W SD-750-W Quote
Width	1.256"
Height	1.340"
Flange	0.250"
Material	Rubber
Type	Sponge
Durometer	2A4 (sponge grade)
Colour	White
Mount	Push On
Bulb position	Side
Core	SD-500L Spring Steel

Spec sheets live on each part's page.