The Wolff double spring is made for older H&R firearms with no transfer bar, it has double anchor legs instead of the single anchor of the OEM spring with a loop that wraps around the back side of the hammer between the anchors in a small notch that can be seen on the gold hammer below. I don't know if it will work with a modern hammer without modifying the hammer, it works great with the old style hammers after removing the transfer bar(lifter & striker), more on that in the low profile hammer mods 2 in the FAQs.
Tim