Side by side.

Specification	SD-108-T SD-108-T Quote
Width	0.400"
Height	0.996"
Flange	0.130"
Material	PVC
Second material	Rubber
Type	Sponge
Durometer	80 Shore A
Colour	Black
Mount	Push On
Bulb position	Top
Core	1in Stamped Steel

Spec sheets live on each part's page.