These web shooters were created from Peter Parker's incredible intellect in order to further advance his spider-like skills. Spider-Man uses these shooters for various purposes, such as deactivating multiple devices, immobilizing opposing enemies and even traveling through New York by swinging from building to building.
While developing his "Spider-Man" vigilante persona, Peter develops these wrist-mounted web-shooters as a means of travel and capture. Their concept is based on a material developed and produced by Oscorp known as "BioCable"; an extremely strong material that can be compressed and stored in tiny cartridges. Though Oscorp did not yet find a use for the substance, Parker ordered a large quantity of it use as his webs. He spent some time developing the web-shooters themselves in his room before perfecting the design. They consist primarily of a thick leather strap with a small circular device on the underside of the wrist that stores cartridges and ejects webbing.
The device has an LED light that lights up whenever Peter shoots his webs. They are activated by pressing a small trigger on his palms with exact pressure from his middle and ring fingers. Once perfected, he wears them at all times under his sleeves in case of emergencies or as a means of fast travel by slinging over the streets.
The web-shooters were seen in the film to have the capacity to not only shoot lines of web, but also dispurse the lines like a spray bottle; which was seen when Spider-Man strung the Lizard up in a web during the fight at his school. The shooters are also incapable of working in water, which was seen in Spider-Man's second confrontation with the Lizard before he escaped through the underwater tunnels. During his final battle with The Lizard on top of Oscorp Tower, both his web-shooters were crushed; however in the ending scene, Peter either made new ones or repaired the damaged ones.
In the 2nd film, Peter wears new, updated web-shooters which are red and pentagon in shape. Peter also incorporates an MP3 player into his web-shooters so that he can listen to music while swinging through the streets of New York.
In his first battle with Electro, they are damaged by the strong electric current fired by Electro. Peter then attempted to find a way to make the web-shooters electricity-resistant, to no avail. Before the last battle with Electro at the OscorPower Station, Gwen reminds Peter of their eighth-grade science class where they learned that if you electromagnetized a nail, it could hold an electric charge. So they used a police car's battery to magnetize the web-shooters, which then was able to withstand Electro's electric bolts.
