I have a 2 1/2 year old Byers Series II Research mount for sale. It has an 11 5/16" RA gear and a tangent DEC. Condition is excellent as it was only used in my backyard a few times. Weight of mount head is 135lbs. Carrying capacity is 235lbs. This is a heavy observatory class mount for large scopes. Includes tripod, three 22lb counterweights, and polarscope. Email for details. Serious inquiries only.