Quality UK made with laser cut out air vent holes. Since June 2014 they have been re-designed and made in Marine grade EN5083 grade alloy with improved hardness to fit Heritage and genuine subframes perfectly, it is paramount that that the gearbox clears the sumpguard to allow for cooling and if required it is advised to shim up the rear legs with washers to make a clearance(usuallly up to 1/4"(6.3mm).
Originally designed for Rover Merchandise/Accessory parts in 1996, it never done the allocated test miles required at Gaydon when the accessory range was dropped. Testing was done (10-20 thousand miles usually)to insure the oil never over heated or over cooled or cause any other problems.