Model 685 2-1/2" edgewise has been designed without any barrel projection and is fully shielded to allow vertical and horizontal stacking without interaction between movements or other external magnetic fields. The specially engineered, rugged D'Arsonval movement with high torque to weight ratio provides excellent response and damping characteristics.  
Please specify when ordering as 685-1 single, 685-2 dual stacked or 685-3 triple stacked.