Tom Osypowski Dual-Axis equatorial platform for 15" to 18" DOBs. Dual-axis drive and auto-guider support makes this set-up very suitable for long exposure prime photography. This version of Tom's platform sells new for $2225. I'm asking $1600 or a trade for a GEM of roughly equal value. Or if you have something else to propose I'll entertain other offers. Platform was built to support 37 degrees plus or minus 3 degrees latitude.