I'm surprised by the apparent misunderstandings around this considering this is a Glock specific sight. Maybe the fact that I only live about 5 miles from the Glock factory helps..... But many don't seem to understand the difference between what is "standard" and what is an "option". Most don't seem to know much about the whole 3.5/4.5 lb connectors either. As to the 3.5 / 4.5 issue yes, the 3.5's aren't marketed by Glock....as that....NOW. But the "practical tactical" Glocks originally all came "standard" with the 3.5 lb connector. A few years ago Glock realized that if you're shooting the 3.5 lb connector with all other factory parts your pull will average closer to 4.5 pounds than 3.5 pounds. So they changed the name. The device itself is unchanged, and yes it was originally marketed by Glock as a "3.5 lb connector", not a 4.5. And if you order 500 Glock blue labels for your police department and don't specify they will all come with the "standard" 5.5 lb connector. If you order a non-blue label 34/35 it will come "standard" with the 3.5 (now called 4.5) pound connector. Yes you can get other options, but that doesn't make them "standard". When I started with my agency in 1999 we issued each officer a Glock 22 and 27. Both came with the, yes Glock factory OEM, 8 pound "New York" triggers. They weren't "standard" though that was an option. Luckily a few years later the range staff won out over the pencil pushers and we switched to the 5.5 pound connectors. Our 22's also came with extended slide releases then, our new ones don't. That was an option, not standard. I don't know if Glock even marketed it as the "blue label" thing back then for police. But either way the extended slide releases were not "standard" on any version of the Glock 22. Yet we had several hundred of them that had then. You can also get a Glock with the factory 12 pound New York trigger, like NYPD does, but that doesn't make it "standard". The IDPA even specifies that a "3.5 pound trigger" is legal for competition on all models of Glock pistol because it is available as a factory option. Yes, you could get a Glock 26, or a 35, or a 17, or whatever, with a 3.5 pound (now called the 4.5 pound but the same thing) trigger. So yes, a "standard" blue label Glock of any model will come with night sights, 3 mags, and a 5.5 lb connector. We even recently ordered a new batch of a few hundred blue label Glock 27's. Even they all came with 3 mags. Like I'm going to carry 2 spare mags for my backup gun when my primary gun's mags will fit it..... But that's what comes standard with the blue label guns. Other options are available of course. Extended mag releases, extended slide releases, adjustable sights, different trigger connectors, whatever. But you have to specify that stuff if you want it on there.
Of course I think all this strays from the original question. Which was basically what's the difference between the Glock that's in a police officer's holster and the Glock that's on the dealer's shelves that anyone can buy. The answer is ABSOLUTELY NOTHING. The only difference is the MSRP and what is considered to be "standard" versus what is available as an "option". The guns themselves are 100% identical. Even the "blue label" program is not just a police program. Blue label guns are also offered by Glock to EMT's, fire fighters (including volunteers), military personnel (including Guard and Reserve), corrections officers, state licensed security companies, state licensed security guards, judges, district attorneys, ADA's, and recruits still in the police academy. So even the blue labels are not just "LEO" guns like the asker was asking about.