What converter should I buy for this Spiratone lens?

So I recently bought an old lens for quite cheap at a thrift store (the specs on the sides say "Spiratone 1:5.6 f=300mm Mirror Lens No.8300968 ø72 Minitel-S Plura-Coat"), and it appears to be built for SLR cameras rather than my Canon Rebel. I've done some research and it appears that a t-ring adaptor would be the best way for me to mount it to my canon, but I'm not 100% confident on this and I don't want to spend my money on an adaptor if it's not going to work. Can anyone help out?

Picture of the lens from online (it's the middle one):

 

Take a picture of the base.

 

If it's a T-mount, then all you would need is a T-mount-to-Canon EF adapter.

 

Like this one.

 

Yes, it's a T-mount lens. The adapter just screws onto the base of the lens.

 

The T -mount (often called T2) is designed for adaptability. I don't think any cameras have been made in this mount & it's readily converted to just about every mount for interchangeable lens cameras with 35mm or smaller sensor/film. A few medium format cameras can also be adapted but I don't think any of the MF SLRs can if infinity focus it needed.
It doesn't allow communication between the lens & camera so aperture & focusing are fully manual (aperture on mirror lenses is fixed anyway so it's very common for such lenses).
I believe it was originally designed for connecting cameras & telescopes/microscopes a role it is still regularly the default for.

 

As a mirror lens it lacks aperture control, so all that has to be contended with is manual focus, and obviously using a combination of shutter speed and ISO to get the exposure right.

 

I have used the T2 adapter with a 500 mm mirror lens.
As others have said you will have to set f stop and focus manually

 

My point precisely in the last half of the quote you used.
FWIW mirror lenses are practically all manual focus too (I've heard of ONE exception but never seen it) so mount has very little to do with their operation.

 

Spiratone! that name doesn't come up too often in discussions, but they made some nice products back in the day. Once you get an adapter I hope you enjoy using it.

 

Ya gotta appreciate good ol' Fred!

 

I'd never heard of him before. I guess the presence of Canons, Nikons, Sonys, and Pentaxes in our hands are in good measure based on his work.