HD7840 pod holder alternative
No pod holders are for sale for the HD7840. You can also use the pod holders for the HD7810, but you must not attach the handle, otherwise the flap will no longer close.
If you no longer have the pod holder for the HD7840, this is the solution. If you still have the pod holder, you can replace the inside of the HD7840 pod holder with the inside of the HD7810.