This is the single most important modification that I made to my Nexstar 5. This bracket allows the scope to be rebalanced when heavier EPs and accessories (e.g. cameras) are added to your setup. I just sold my Nexstar 5...but the new owner did not want the bracket.
Compare to $95 shipped for a new bracket from BuyAstroStuff to $65 shipped (CONUS) for mine. That's 30%+ off the usual price. Bracket shows expected wear around guide tracks where screws secure the bracket in place.