ericm979
Super Member
I have something like that only it's got three blades. I got it from my Stihl dealer years ago. When I went back for more blades they said the company had gone out of business. Something about some blades came loose and went flying.I use an Aussie product/head called "WeedWakka" and it works great. Possibly available via eBay.
As Ultrarunner says, can't use it when the grass is dry as it might spark on a rock.
I mostly use really thick Orgeon X-shaped string. I think it's .105" dia. It's heavy enough that it doesn't break when I hit branches and will cut up to about 3/8" diameter woody brush (like French broom). It needs a strong string trimmer/brush cutter to turn it, and it does not work well on very fine grass.