Catek OS2 's that I bought used last season. I used them maybe a dozen times so they're in virtually the same condition I bought them in. The following information is from the Catek website:
Standard | Step-In
We offer the OS2 bindings in Standard or INTEC-compatible Step-In (SI) versions. The choice between the interfaces is mostly an issue of personal preference, but there are a few general differences. The SI system is more rigid than the bail closures, particularly in regard to lateral movement, and requires that you install INTEC heel units on your boots. The bail/toe lever Standard system accomodates a wider range of boots, including ski boots and older, non-INTEC compatible boots. Our snug, contoured heel bail offers the best boot fit available.
Short | Long Plates
The Short Plate is ideal for smaller boot sizes (<10US) and lighter (<180lbs) riders. The 3/8" thickness provides a more forgiving ride than the long plate. The Long Plate accepts all boot sizes (up to 31.5MP, depending on the boot), and its 1/2" thickness provides the most powerful ride on the market. Riders weighing more than 180lbs or with a boot size greater than 10US must use the long plate.
They are step-in's with short plates.
Overall, the bindings are in great condition. There are a couple of small scratches and there is a small amount of wear on the heel receivers. I used Intec heels and everything felt nice and tight.
As for the hardware, the front binding has a short kingpin and the rear has a long kingpin. They came with no spacers so I just bought some stainless washers which worked fine (1 in the front and 3 in the rear). There are only 3 screws for attaching each disc (they are combo discs that can be used with the Burton 3D system or the standard 4x4 pattern) to the board which worked fine for me on my Burton 3D set-up........you'll need 2 more screws if your board has a 4x4 pattern. All 4 o-rings are there and the elastomers are in good condition.
$150 includes shipping to the lower 48. Anything else, let me know.
Thanks