 "Manfrotto 502HD Long Quick Release Plate 504PLONG" " Manfrotto 504PLONG For sale! - EuroOptic.com
"This Manfrotto Long Quick Release video camera plate fits 502HD, is made from black aluminum, and has a length of 50cm." 
 "Manfrotto Video Camera Plate - 504PLONG" " Manfrotto 504PLONG | WTS Broadcast
"This long version of the standard plate allows perfect balance for camcorders with unusual weight distribution caused by long telescopic lenses or heavy batteries. Supplied with 2x1/4&rdquo; and 2x3/8&rdquo; camera fixing screws. Dimensions: 140x10.7x50mm (5.5x0.4x2in)." 