Spyderco has been at work releasing many of their lightweight classic CLIPIT folder in a new high performance metallurgy steel called K390.
K390 is a high-end, cold worked tool steel enriched with vanadium, molybdenum, and cobalt. Having 9.00% vanadium makes is extraordinarily resistance to wear and adds toughness and edge-holding properties to achieve an outstanding tool life. It is considered a semi-stainless steel with a 4.25% chromium content.
Spyderco proudly offers K390 as a steel option on their Delica 4, Endura 4 (shown) Endela, Stretch 2, Dragonfly 3, Manbug, and Police 4 folders.