SBIG filter wheel fits internally in your ST-5C or ST-237 camera.
This is SBIG's earlier version which:
1) Does not have IR blocking built in to the R, G, and B filters.
2) Comes with a 1.25" IR blocking filter which fits on the camera nosepiece.
New CFW5C sells for $399.00
Selling this one for $200.00 - includes shipping.