Victor mouse traps have a soft plastic yellow trigger. After a few trips, the edge gets rounded from the release. This replacement is smaller, after all, you want the mouse to get closer to the bait. I had to change the pad mount path to accommodate weak layer issues. The old pad pulls up to release, and this one will push in toward the spring to seat. Since traps have some build tolerances, I had to grind about 0.5mm off the release to make it functional.