This little tool seems expensive on the face of it but I think it's actually reasonably priced. I have used it on my gap, lob and sand wedges and it has definitely sharpened them up. You may read that a screwdriver will do the same job..... well it won't. The meta on a driver head is too soft and will not cut / sharpen your grooves.
Tip - I have tied mine to my golf bag and sharpen the odd club not and again when I'm waiting to tee off