Side by side.

Specification	PTL-125 PTL-125 Quote
Width	1.805"
Height	0.650"
Flange	0.167"
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.