I just wanna know for sure (100%) that is the C300 and C310 series power adaptors DC-plug the same on each?

I bought a adaptor for my car and there is just 1 tip that fits and that is kinda loose... and I stumbled on this http://www.targus.com/us/product_ima...essories_a.jpg while surffing targus backpacks o.O
That is what targus "tip configurator" suggested for the C300 series, and I have C310. So if they are the same I'm gonna buy this tip.