Cody -
Is the URL ending in /productname the individual product page? If so, what we are saying will work to canonicalize your product page. You're simply telling Google not to pass pagerank to the /productname?=productspecs page. You're telling them to ignore the specs part of the page as a separate page and to instead pass the link juice to the main page.
Once again, please correct any misunderstandings we may have of what you are trying to do.
Also, you incorporate the canonical tag on a page level. Hopefully you can set this through the CMS (I use Yoast SEO to do this with Wordpress).