Cylinode versus Cylinder

I let Josh read the story of our date (him working on my car), and his reply:

It kills me every time you call the boot with the cylinode a cylinder. Very hugley different things (when it comes to automotives). So anyone reading your blog who might know something about cars now thinks I'm a tard.

Hahahaha. I assured him no one would know the difference.

You don't know the difference between a boot with the cylinode versus a cylinder, do you?