Losmandy 2.5lb weight suits WS-DVWS and DVDWS
Is your scope out of balance since you added that heavy 2" diagonal, guide scope or imager If that's the case you made need to add some counterweight.
The Losmandy 2.5lb weight is threaded to suit the DWS, DVWS system which can fit any Losmandy D style or Vixen V style dovetail bar.
Correct balance is important for your mount as it reduces wear on the motors and gear systems.
You will track better which results in better guiding and better imaging.