Rear Brake Question

[wedoo2]

95 Seca II. The rear brake on this bike did nothing when the pedal was depressed when I got it. I have taken the whole system apart, cleaned and have ordered kits to rebuild everything. My question is that when I took apart the rear caliper, there is, of course. two pistons, but there is only one side that has the spacer between the piston and the pad. Shouldn't both pistons have that spacer? I have looked at the manual and just can't see if I am right. This is the first bike I have come across that has that spacer but I imagine it is there for a reason.