ND Filters & CPL filters are pretty important for what I do. So when I can't get a filter on a lens, it's something that really bugs me. If you happen to cross thread and damage the filter ring on your camera lens, or like me happen to put a small dent on it, luckily there's a simple way to fix it with this tool.
This tool is extremely well made. All metal and pretty heavy. Two different sides should be able to fit just about any common lens diameter. You can use it to straighten out a bent filter thread or clean up cross threads. You can find this Lens Filter Thread Repair Tool tool on Amazon (click here).