They offer rulers in 7 inch, 13 inch, 25 inch lengths, all of them in white plastic. It should be noted that they also do custom rulers, with a minimum order of 5 rulers.
This is the sort of product that I have been desiring for some time, so I went ahead and ordered a 7 inch and 25 inch rulers. Seeing that they are just down the road from me I hope to have them shortly so I will report back my thoughts on them.
All of them are resin cast pieces with excellent details and very few imperfections. These pieces may not be officially for Infinity, however they are a perfect fit and are a great way to add scatter terrain to your table. If you are in the U.S. and your FLGS doesn't carry Spartan Scenics you can see if The Warstore has them in.