Hi Zihe -

I have noticed similar findings with my wave which I've had for several years now. The handle wobble is most noticeable in the closed position, but disappears when the pliers are opened. I'm not sure if this was done intentionally or not. I was thinking that it was somehting with the earlier models that they worked out with the newer ones, but I guess not. I have used it extensively and it really doesn' t bother me. I've also heard that the swisstool is a bit beefier than the wave. If you get one, let me know how you like it. I was thinking of getting one myself.

Both my blades, however, open and close smoothly. For some knives you need to open and close them a bit before they loosen up. Hope this helps.

TTQUAD