Again with a Stargate DVD this disc has a commentary for every episode, something unusual for a TV, but in a good way. The other special features offered on the disc are two featurettes, "Inside the Stargate Special Effects Department" and "SG1 Directors Series: Prototype featuring Peter DeLuise". The special effects featurettes starts by defining special effects and setting the record straight that they are physical effects not visual effects/CGI. I am always a fan of behind the scenes info and clips and this is a great extra for that. We get to see how the various effects, especially the explosions, were achieved onset. There's something entertaining about seeing actors running from a spacecraft when all we can see are the gun blasts hitting the ground.
The second extra is part of a series, this looking specifically at Prototype. It gets us properly behind the scenes as the director, the ever entertaining peter DeLuise talks us through the episode. This disc as is common with the Stargate DVDs is fully packed out and obviously a must if you are collecting the series.