The HF64 is the replacement hinge you want if you purchased a ClearSonic drum shield in 2000 or before, and will accommodate 1/4-inch thick panels.
The HF63 is used for our LITE2466x5 drum shield and is only suited to fit 3/16-inch thick panels.
The HF48 is our 4' version and will only be available through June 2024 when it is officially discontinued.