RepRap Pro Ormerod iamburnys Y-axis Belt Clamp - Parametric
designed to be screwed together on either side on the Y-axis Bed supporting rib, to aid with belt spillage and belt tightening issues.
v6 - cylindrical toothed belt trap, does not require a belt twist
v7 - straight toothed belt trap, does require the belt to have a twist, often favored as the smooth side of the belt then is in contact with the runner bearing.
modelled in OpenSCAD
more info available here http://forums.reprap.org/read.php?340,294362,307120#msg-307120