New Spey Rod

[The Coles]

Well... new to me at least.  I scored a deal on a nice two-handed Diamondback that I believe is set up for spey-casting.  I bought it used from a gent in Oregon for under $100 and since I hadn't seen it first hand before the purchase, I didn't have high expectations.  I was very pleased and surprised when I picked the rod up yesterday... this is a nice rod.  It's an older Diamondback with spigot ferrules and has the diamond-braid pattern in the weave of the graphite.  All of the hardware seems to be in good shape.  What I am curious about is the defining attributes... in general, what makes this a spey rod?  The butt grip is 3.25 inches long and the upper grip, 10.75 inches.  The reel seat looks to be a Struble U3 but the builder didn't bother with recessing the hood.  I have a few doubts as to the reel seat as the spey rod seats I have seen seem a bit more substantial and longer, but I could be wrong.  Also, the length is a full 16 feet assembled.  Anyway, if any of you spey-casters out there could help me better understand what I have, I'd appreciate it.  Thanks all..   Steve Totten Inlet