I have a Van Slyke M4 Monster Focouser for sale in excellent condition. Included is a C11/C14 rear cell adapter. The hand controller has been modified from the stock Van Slyke controller to allow for operation without having the "extra" cable connected between the hand controller and its power source; instead it runs off 2 each - 9 volt batteries installed within the controller box. This is a very handy modifciaton and eliminates dangling wires and possible wire snags. Selling price new is $900. This focuser is value priced at $400 (Pay Pal ad 3%), including free shipping USPS Priority Mail lower 48. Thanks for looking!