On the Maxx, the "blade stop" IS a thumbstud too.
Here's a pic:
(Pic courtesy
http://www.1sks.com - a good online vendor.)
Now let's look at the part of Penal Code 653k that matters re: thumbstuds.
Here's the whole thing, I'll highlight what's critical:
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653k: Every person who possesses in the passenger's or driver's area of any motor vehicle in any public place or place open to the public, carries upon his or her person, and every person who sells, offers for sale, exposes for sale, loans, transfers, or gives to any other person a switchblade knife having a blade two or more inches in length is guilty of a misdemeanor.
For the purposes of this section, "switchblade knife" means a knife having the appearance of a pocketknife and includes a spring-blade knife, snap-blade knife, gravity knife or any other similar type knife, the blade or blades of which are two or more inches in length and which can be released automatically by a flick of a button, pressure on the handle, flip of the wrist or other mechanical device, or is released by the weight of the blade or by any type of mechanism whatsoever.
"Switchblade knife" does not include a knife that opens with one hand utilizing thumb pressure applied solely to the blade of the knife or a thumb stud attached to the blade, provided that the knife has a detent or other mechanism that provides resistance that must be overcome in opening the blade, or that biases the blade back toward its closed position.
For purposes of this section, "passenger's or driver's area" means that part of a motor vehicle which is designed to carry the driver and passengers, including any interior compartment or space therein.
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There's two issues in the bold area:
1) As long as you can open the blade "by thumb pressure on the blade or something attached to the blade", you're good. So in the case of the Maxx, you can thumb it either on the stud, or on either of those two "guard wings" at the base of the blade.
You can ALSO open these with your forefinger on the "top guard" when the knife is closed. Which would be a problem maybe if that was the ONLY alternative. Maybe. You can also thumb that though.
2) Second issue is the "detent or bias towards closure" bit. All of the Camillus linerlocks and "integral frame lock" knives (also known as the "Sebenza lock") have the "ball bearing in a divot" detent system and are all hence legal. So does pretty much every knife with such locks that's worth more than $20, including the entire CRKT and Camillus lines. A few higher-end folders have deleted this; TOPS made such a thing, you have to tighten the pivot pin screw to prevent snapopen on such pieces, and use blue locktite to prevent loosening into felony status
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