The Lehigh site says they are out of stock and points you to the Knight site.
The one at the Knight sight doesn't seem to have the vent liner that the Leigh plug I bought has. I have one of the original Knight non-FPJ plugs (sold by Knight long before Lehigh was selling theirs). It doesn't have a vent liner, and the flash channel was small and produced hang fires with BH209.
The Lehigh plug I bought with the vent liner seems to have a bigger flash channel. I have not had hang fires with BH209 using it. I wonder if what Knight is selling is the original Knight non-FPJ plug or the one from Lehigh with a bigger flash channel. Since the Lehigh site points to the Knight site, the one Knight is selling must be a new version. I just didn't see the vent liners in the picture of the one at the Knight site.
-Mike