The exact contents of Batman's utility belt are unknown, and he seems to change them frequently, based on the case he is working on. In fact, his uncanny ability to have exactly what he needs is legendary (if not a bit laughable. Such as in the 1960 Batman TV show they had the Bat Shield and Boring Pills.).
The pockets on the belt are locked, and only Batman knows how to open them (an unfortunate trick for Batman's enemies, who believe that the belt gives Batman the edge). Similar belts are worn by Robin and Batgirl.
The belt was drawn as a yellow belt with cylinders up until the turn of the millennium. However, In '86 Frank Miller drew the belt with military style pouches, but this change would not come canon to mainstream continuity until No Man's Land. Prior to this belts with pouches were only shown in flashbacks to Batman's post-crisis early years starting the early 90s. A common joke amongst fans is Batman's apparent ability to carry around random objects with the word "bat" affixed to the front exemplified in the 60's TV Movie's "bat-shark repellent".
The belt is relatively simple: a Kevlar strap with a metal buckle. The belt houses ten cylinders which vertically clip to the outside of the belt. There are pockets between the cylinders, as well as hidden pockets on the inside of the belt used for housing one of various Batarangs. The cylinders house different tools for crime fighting.
Batman’s utility belt is one of his most characteristic items of special paraphernalia, and everyone in the "Batman Family" has the same designs on their utility belts Batman had designed the pockets to be locked, and only he knows how to open them. His belt has a security device on it where it can electrically shock someone or detonate an explosive device to prevent anyone from tampering with it. It is made of a leather strap with a solid steel buckle. There are also compartments that hold collapsible "Batarangs." It can hold ten cylinder cartridges that are equipped vertically outside of the belt. The cylinders hold various tools and equipment Batman needs to fight crime and vary depending on his mission. The list of items is extensive and has been changed and upgraded on many occasions. Many different belts have been created for different occasions, but all (at times) act in the same way that the original belt operates. Some of the more common gadgets include the following:
- Batarangs: Shuriken or boomerang based throwing blades made to resemble the symbol of a bat. Some Alternate versions of his Batarangs explode, emit electrical blasts, and sometimes come with detonators.
- Grappling Hook: Also known as the Bat-Claw. Batman can use this to grapple onto high locations or can grab hold of a criminal by directing it at him, he sometimes uses it to catch run-away street thugs that cannot put up a fight against him.
- Gas Mask: This is used to protect Batman from dangerous fumes and other airborne chemicals. This fits over the bottom half of the mask.
- Re-breather: allows Batman to breathe underwater or in a vacuum
- Night Vision Goggles: This allows for Batman to see in dark or dim-lit areas. It also grants him the ability to view the infrared spectrum. Now built into his mask
- Sonar: Used in his mask to locate criminals.
- Tracers: Bat-shaped signal tracers that can adhere to most if not all surfaces.
- Communicators: Batman communicates with different members of his team and also with other superhero allies using closed-circuited signals.
- Lock Picks: Batman uses these to open locked doors.
- Cuffs: Special cuffs that only few enemies and heroes can break out of. Batman can quickly lock a enemy to a pole or deliver him to the police.
- Bolas: Batman swings these Bat-Bolas over his head to wrap up an enemy.
- Smoke Grenades and Pellets: Batman can throw these grenades in order to use a stealth technique, distract an enemy, escape a situation, or plan his next course of action.
- Sonic Grenades: These disrupt electronics and disorient enemy hearing.
- Flash Grenades: This gadget is used to temporarily blind enemies.
- Mini-Mines: Mines that can fit in any small area or used as low-grade explosives during combat.
- Thermite Explosives: Capable of burning through most materials.
- Plastique: Small exploding devices that have a timer or detonator switch to activate.
- Tasers: Batman carries this to shock or neutralize an enemy. This Weapon was more than often used in the Golden Age / Movies.
- Brass Knuckles: Used to engage an enemy with more force behind his blows.
- Tactical Knife: Batman does not use this in combat, but he has used this to cut through many durable materials.
- Mini-Computer: Batman carries two of these. One is located in his utility belt and another is located in his left arm. It appears as a virtual computer that he can contact other heroes or find out strategic areas in certain places.
- First Aid Kit: Used to aid in treating wounds. Alfred normally uses this to tend to His Master's wounds.
- Forensics Kit: Batman keeps two of these, one in his utility belt and the other in his vehicles.
- Kryptonite Ring: Inside a lead-lined box is a ring with a green kryptonite jewel to battle Superman if he ever went rogue.
In Other Media
The utility belt is famously featured in the comedic, Dozier Batman show. Due to the tongue-in-cheek nature of the show, the gadgets contained in the belt were often ridiculous, such as a can of shark repellent spray. Sponges were very often used for the flat as paper "pouches." This was very different from the belt in the comics which had only tiny capsules. Frank Miller would later use the idea of pouches and present it in a more practical, grounded in reality way.
The brass utility belt is featured prominently in both Batman & Batman Returns, starring Michael Keaton as Bruce Wayne. It is very accurate to the comics of the time, but the old fashioned "pirate buckle" is upgraded with a retro-futuristic design. It carries up to six gadgets on the back, which can be brought forward from the rear by a high-tech slider device. Four capsules containing chemical weapons are housed on the sides, including blue napalm, red explosive, green knock-out gas and a white smoke bomb. These color coded chemicals can be mixed to create a greater combination of effects.
The Dark Knight Trilogy
A modified version of the utility belt is featured in Batman Begins, The Dark Knight, and The Dark Knight Rises. They went with a copper color rather than chrome yellow or brass. In the films, it is developed by Wayne Enterprises as part of a suit of prototype military armor. The belt features magnetic, impact-resistant compartment boxes, and stores a number of items ranging from a grappling hook and Batarangs, to medical supplies and an encrypted cellphone.
Utility belt props have been released by a variety of manufacturers ever since the 1960's.