This specific gun seems to be (based on my expert knowledge of firearms, and the size of the bullet) a .32 ACP caliber pistol. This gun (or "gloc", as it is referred to on my side of the pond) is powerful, light, and perfect at the range. I do not own a weapon, I'm quite pacifistic in principles. However, my knowledge of these weapons is expert: I've done more hunting than Teddy Roosevelt, and been to more firing ranges than Ted Nugent. I do believe whoever labeled this diagram is an expert, also. They've labeled everything perfectly (except for the ejection port, the magazine catch, the hammer, the recoil spring plug, the front sight, the rear sight, the recoil spring plug, and the slide stop), and everything is in its right place. Expecially one specific part: "the piece that blocks the trigger so no accidental Bangs!". You can tell the labeler really knows there stuff here. Many amateurs (or "greenhorns", as I like to call them) would incorrectly refer to this item as a trigger guard, but only those who've had experience with firearms, and have seen more than their share of firing ranges, know the truth: that this specific assemply piece is formally termed as The Piece that Blocks the Trigger so no Accidental Bangs!.It's a little known fact, and only those who've been fortunate enough to collect such valued information on firearms would know the truth. Google it, it is there. Ask Charlton Heston, he'll tell you the same thing. And next time someone refers to this piece as a trigger guard, correct that silly someone, because now you know the truth, and that's all that matters, because knowledge is power.
And to whoever labeled this drawing, I think we should go bowling sometime, because we already have a lot in common, with our obvious proficient knowledge of weaponry. Well done.