Detective Comics
Detective Comics is an American comic book series published by DC Comics. The first volume, published from 1937 to 2011 (and later continued in 2016), is best known for introducing the superhero Batman in "Detective Comics" #27 (cover dated May 1939).
Batman's utility belt
Batman historian Les Daniels credits Gardner Fox, the first writer other than Bill Finger to write the adventures of Batman in "Detective Comics", with introducing the utility belt concept in "Detective Comics" #29 (July 1939). In its first appearance, Batman's utility belt "contain[ed] choking gas capsules." Two issues after the utility belt debuted, Fox also wrote the first appearance of a bat-themed weapon, when the batarang debuted in the story "Batman vs. the Vampire" in "Detective Comics" #31 (Sep 1939).