Had a hell of a time getting stainless-steel splitring to fit. (mind you, we're talking about #5 complementing ring here).
Out of three, two had VERY strong springs --- needed astonishing amount of force to push it with-respect-to the tiny size!!!!!!!!!
The third of three was more as-like expected for thin wire spring ---- but I wish it was more tense like the other two.
I plan on buying heaps more in the Pico size. [I hope I don't get arthritis later in life, or these'll be pesky. he he he]