Did you get to keep the product?
I once ordered some lights on EBay for $50 (bumper lights) and never got them. I disputed via PayPal…and then 3 weeks after my dispute was closed in my favor…the lights came in…haha.
They prevent heat from transferring from your heads to intake manifold and throttle body. Most spacers are port matched to your stock intake ports. A smooth transition from one manifold to another is very important for optimal airflow.
She would have gotten better results had she gotten an IM spacer as well…but a TB one will still cool a little.
On my Maxima…I can see temps drop about 40 degrees with an IM and TB spacer. That equals 8hp and 9tq according to actual dyno sheets.
NWP Engineering makes the Maxima ones.