Discussion. The defendant was carrying an “expandable baton”2 when he *1011was taken into custody and booked. Although an expandable baton is not among the weapons specifically listed in the first portion of G. L. c. 269, § 10 (b),3 see note 1, supra, the Commonwealth charged the defendant with carrying “a dangerous weapon, to wit: a BLACKJACK, not being authorized by law to do so, in violation of G. L. c. 269, § 10 (b).” Over the defendant’s objection at trial, a police detective compared the expandable baton to a blackjack, but conceded on both direct and cross-examination that the expandable baton at issue was not truly a blackjack. The detective stated: “[Ijt’s not my testimony that this is a blackjack, it’s my testimony that it is similar in the way that it’s constructed” (emphasis added).

The question is whether the evidence warranted a finding that the expandable baton was a blackjack within the meaning of the first portion of G. L. c. 269, § 10 (b). In construing the statute, we begin with the observation that “[a] general tenet of statutory construction is that the ‘statutory expression of one thing is an implied exclusion of other things omitted from the statute.’ ” Commonwealth v. Ronald R., 450 Mass. 262, 266 (2007), quoting Harborview Residents’ Comm., Inc. v. Quincy Hous. Auth., 368 Mass. 425, 432 (1975).

The statute identifies a number of specific weapons that are prohibited. In some instances, the name of the weapon is followed by language describing weapons similar to the identified weapon. Thus, for example, the statute identifies several specific types of knives, but then also refers to “any [other] knife” having certain characteristics. Similarly, the statute refers to “knuckles of any substance” that can be “put to the same use with the same or similar effect” as metallic knuckles; nunchaku, zoobow, “or any similar weapon” configured with two sticks connected by rope, chain, or wire; and shuriken or “any similar pointed starlike object intended to injure a person when thrown.” G. L. c. 269, § 10 (b).

Other weapons, however, such as a “blackjack,” are particularly named in the statute, without any accompanying reference to “similar weapons,” or those that can be put to the “same or similar” use or effect. While the second portion of § 10 (b) contains very broad, catch-all language (“or other dangerous weapon[s]”), the first portion of the subsection — the only part applicable to this defendant, see note 3, infra — does not. The first portion purports to proscribe only carrying certain dangerous weapons, but not others.4 See Commonwealth v. Smith, 40 Mass. App. Ct. 770, 770-771, 777 (1996) (homemade weapon satisfied definition of a “knife,” particularly in that Legislature used the general term “any knife”); Commonwealth v. Miller, 22 Mass. App. Ct. 694, 694 n.1 (1986) (“clear that the Legislature did not intend to encompass all knives in its enumeration of ‘per se’ dangerous weapons”); Commonwealth v. Blavackas, 11 Mass. App. Ct. 746, 752-753 (1981) (small kitchen bread knife with approximately eight-inch blade not type of knife specified in first portion of G. L. c. 269, § 10 [b]). In this case, the omission of language broadly including weapons similar to blackjacks in purpose or effect, when *1012read in light of the inclusion of such language in both the first and second part of the statute with regard to other types of weapons, indicates the Legislature intended specifically to proscribe “blackjack[sj” but not all weapons similar to blackjacks. The Commonwealth’s contention that the defendant’s expandable baton is the “functional equivalent of a blackjack” is therefore unavailing.

The evidence in this case is not sufficient to establish that the “expandable baton” carried by the defendant was a “blackjack” carried in violation of G. L. c. 269, § 10 (b). While the term “blackjack” is not defined in G. L. c. 269, § 10 (b), the Commonwealth’s witness testified that the weapon seized from the defendant was not a blackjack.

Judgment reversed.