Side by side.

Specification	SD-1435-NAV-120-Bulb SD-1435 w/ NAV 120 Bulb Quote
Width	1.070"
Height	0.765"
Flange	0.285"
Material	PVC
Second material	Rubber
Type	Sponge
Durometer	80 Shore A
Colour	Black
Mount	Push On
Bulb position	Side
Core	1.4in Stamped Steel
Industries	Marine

Spec sheets live on each part's page.