If you are in the situation to replace the original 3Drag controller with an Arduino Mega with Ramps, the typical holder won't work anymore.

This is a holder for the Arduino board, with RAMPS as shield on the same position as the normal holders on the right hand Z beam.

The version 02 is just for the Arduino, while version v04 has some extension to clip additional small board on it, as shown in the made picture.