Hello, I have been reading the forums for some time and, like many before me, I am ready to invest in a Glavo Fiber laser. As many of you who already have or are going through the order process know, the choices can be very daunting. I ve received a number of quotes over the past few weeks with prices and options all over the place. Some with lower prices but higher shipping, others with different models of laser sources. The 30w M6 quotes range from $8k to $10,800, with some including a rotary and others not. After perusing the forums for awhile now, and funds permitting, I am pretty settled on a 30 watt MOPA in the Split type design with a Rotary for doing Stainless Tumblers and mugs with some color here and there. The problem or question I have run into is with the JPT sources. I noticed some companies quoting YDFLP-30-M6+-S and YDFLP-30-M6+-L1 laser sources and others showing C-30-M6+-S and C-30-M6+-L1 sources. None of them seem to be able to tell me the difference between teh YDFLP- and the C- source. Thinking it was just each companies naming, I decided to look at the JPTOE website and sure enough they list both YDFLP and C version with identical specifications. The -L model of each has a 31-2000kHz range and the -S version 60-2000kHz range, otherwise everything else is identical. Does anyone have any of these models and if so which one? What is the widest kHz frequency range you have used with your fibers? What is the wildest thing you have been able to mark? leather, wood, pu notebooks, etc... Of the people that have Glavo Fibers, what would you do differently if ordering again. If you have a MOPA, do YOU use color and do you play with it to get the best colors? Have you paid off your investment and how long did it take you? I am somewhat torn between LaserPower Company who is offering the YDFLP-30-M6+-L and XT Laser who uses the C-30-M6+-S. XT Laser has a blog that's updated regularly and they are constantly posting videos of their lasers. LaserPower seems to be offering a better source for a little less but I can not find anything on them and they do not post videos very often. Thanks, Jeff