The Dovetail Plates are the heart of the Losmandy Secondary System. The D series bar is 12.7mm thick x 102mm wide x length of the tube assembly. Dovetail plates may be mounted to the top and bottom of tube assembly for mounting of all D series accessories, making it possible to use both sides of tube for equipment such as counterweights or secondary/guidescopes. The dovetail plates, like all accessories in the Losmandy line, are machined for lightness and rigidity from aluminum stock, then black anodized for a tough, corrosion free surface. Celestron dovetail plate for 8 inches, bolts to existing holes - mounting hardware supplied. - Weight: 900g - Length: 343mm - Hole Separation: 313mm/323mm - Height: top of tube to top of dovetail plate 25.4mm - Thickness: 12.7mm