Something that isn't alcoholic, sharp, shoots, top opening, side opening, less that 2", fully automatic (including washer/dryer combos), or capable of holding more than 5 bullets, it's CA legal. This is because even though we like to think we're liberal, with guns, knives, and most other things, we're hard asses, with the acceptation of Utah beer.
Most knives and guns aren't legal in CA, but in bordering states (Nevada, Arizona, and Mexico), so it makes it pretty useless in some cases.
'Is that knife CA Legal?'
'Nobody said I was CA Legal..'