Side by side.

Specification	SD-111 SD-111 w/ .060 Opening Quote
Width	1.250"
Height	0.500"
Flange	0.110"
Material	PVC
Second material	Rubber
Type	Sponge
Durometer	80 Shore A
Colour	Black
Mount	Push On
Bulb position	Side
Core	1in Stamped Steel

Spec sheets live on each part's page.