The air vent (or British English, air vent) is a solid bag that can be punched repeatedly. The air outlet cylinder is usually cylindrical and filled with various materials with corresponding hardness.

Sandbags have been used in martial arts and swordsmanship, throughout the written history of military training. Similar devices in Asian martial arts include Okinawa and Chinese sticks, which may have hitting surfaces attached to them.

In martial arts and fighting (such as karate, taekwondo and Thai boxing), in addition to the development of boxing, "heavy" bags, standing bags and similar equipment have also been used to practice kicking and other fighting movements.

Vents are usually filled with grain, sand, rags or other materials, usually suspended from the ceiling or fixed to shelves. The other bags have an internal air bag that can be filled with air or water. The vent is designed to withstand repeated physical abuse without breaking. The bag must also absorb the impact of the strike without injury to the user.

There are many types of air outlet, which have different names according to their size, use and installation method. Almost all vents are covered with leather or synthetic materials, such as vinyl, which is resistant to wear and mildew. Canvas can also be used as bag material in low usage and humidity.

The quick moving bag is a small inflatable bag whose top is fixed on a rebound platform parallel to the ground. Speed bags can help fighters learn to keep their hands up, improve hand eye coordination, and learn to transfer weight between their feet during boxing. They are also known as fastballs or speed bags. They are usually filled with air and mounted around tight Pu based or leather materials. They come in all sizes, from large 13x10 "(33x25 cm) and 12x9", medium 11x8 ", 10x7" (25x18 cm) and 9x6 ", to small 8x5", 7x4 "and 6x4" (15x10 cm). Usually, the larger the bag, the slower it is, and more force is needed to move it forward. Large bags are used to increase strength and endurance, while small bags allow training athletes to focus on faster hand speed, timing and coordination. Beginners may think of this bag as a "control bag" rather than a fast backpack, because they can't control their swing power and speed, so they can't drill quickly and repeatedly.

Boxers usually use their fists to knock the speed pack from the front, but they can also use their fists and elbows to knock the bag from all around the head, including the front, back and side. In this approach, users can perform many different punch combinations to produce improvised rhythmic accents.

Although fast bagging is usually hung vertically, there is another way to hang the bagging horizontally on the wall recently. In the early 20th century, especially from 1920s to 1940s, it was very popular. The same punching technique can be used when hanging vertically on a horizontal bag. Coordinative bag is a new type of fast bag, its moving speed is unpredictable, and it can't move rhythmically. In addition, because of the tedious installation and anchoring when installing the traditional speed bag platform, a portable speed bag platform installed at the door has been created. The design makes the downward pressure stable the portable speed bag platform, which can be installed and disassembled through the pull system that can be used at any door.

The slant ball / drop earth / double head bag is almost the same as the speed bag, the only difference is that the size, shape and material of the bag may be different, and the cable system is connected to two clips on the ceiling and floor - when the boxer hits the ball in any way, it will react by swinging them quickly, with the goal of turning, slamming, dodging and improving coordination. The faster and harder these packets are hit, the more times they bounce and react in different actions and angles, thus providing a broader practice for fighters. There are also two balls from the floor to the ceiling that train the body head combination

Corn bags or slide bags are not used to drill holes with great force, but are used in boxing training to improve the head movement ability of athletes and avoid the opponent's boxing ability. Their name comes from the fact that they are traditionally full of corn.

A heavy bag is a large cylindrical bag, usually suspended by a chain or rope, used for powerful body punches, and can be used to toughen the hand or any other body part used to hit the bag. Heavy bags are used to develop power. It's best to learn techniques on perforated gloves or cushions. Some variants of the heavy bag are the banana bag used in Thai boxing, which is longer than the ordinary heavy bag, and can train low kick and knee strike, while the slender bag is thinner than the heavy bag.

Independent heavy bag refers to the heavy bag installed on the counterweight base instead of hanging from above. The bottom is usually filled with sand or water to make the bag more stable and prevent it from moving around. Although they serve the same purpose as hanging heavy bags, they can also be turned over and used for ground exercises. Other variations of standard heavy bags include horizontal suspension from both ends to practice punches and non cylindrical shapes. There are also independent reflecting bags (independent speed bags).

Upper cut bags began to appear in the early 21st century. Because there are many different bags and training equipment for boxing, upper cut bags have been and are still common in clubs and stadiums.

Compared with the standard 4-foot straight Pu (polyurethane) punching bag, the fighter can drill with different length, speed and force, which is specially designed for punching practice, slamming, curling punching and fast up and down punching. Some types of hook up bags: angle bags are variants of hook up bags for training hooks and hooks, uppercut horizontal vents, teardrop bags, body grab / break bags and bowling bags for training knees and hooks.

Wall bag is a kind of bag attached to the wall, which can be used for training hooks and hook edges.

Body training aids such as modern "body to handbags" are mainly made of synthetic materials, and sandbags are sometimes mounted on the base of counterweights rather than hanging from above. These bags try to simulate a living opponent and provide the opportunity to practice important area strikes, which are usually unsafe for the partner. Strictly speaking, these are not sandbags, but modern versions of equipment, such as wooden man equipment in Yongchun, quintain in the middle ages and target dummies used in modern bayonet training. A large inflatable balloon with a base is another kind of air outlet, usually painted with pictures and sold as a children's toy.