This is a CAD designed replica of an RBS Square 4-Hole Injector Hat, in 1/16 scale.
The intake openings are hollowed out.
Small holes across the front openings are provided for a rod to connect the butterflys to your throttle linkage and barrel valve.
Demensions:
The injector body is resin and the butterflys are photo etched.
By, Futurattraction, 1/16 scale.