We've used Grizzly truss rods before, and they work good. The only downside is that it's not like most dual action truss rods, where you can route the same width slot for the truss rod. This one, you have to route out where the adjustment is, slightly bigger, so it takes a little longer to install. It's somewhere between a 7/16" Stew Mac truss rod, and LMI 3/8" depth, as far as slot depth goes. The adjustment part needs to be slotted deeper approx 7/16", but the rest of the truss rod could be installed in a smaller 3/8" slot. That's the specs they don't tell you in their catalog. On a side note, I talked to a Grizzly rep the other day, and was asking when the 2006 Luthiers Catalog was coming out, he said they discontinued it, and that they put everything in the one big catalog this year.