A sealed protective suit with its own air supply, worn by Starfleet crews in vacuum and in poisonous or contaminated surroundings, and redesigned in almost every series.
Environmental suits, or EV suits, appear throughout Star Trek. The Original Series shows silver suits with mesh helmets in The Tholian Web, when Kirk is lost aboard the USS Defiant, and the animated series replaces them with glowing life-support belts.
The films introduce bulkier suits with thruster packs, such as the one Spock wears to enter V'Ger in Star Trek: The Motion Picture. In Star Trek: First Contact, Picard, Worf and Hawk walk across the hull of the Enterprise-E in magnetic boots to stop the Borg.
Star Trek: Enterprise gives its crew practical orange suits, and Discovery adds armoured suits with built-in thrusters, and later ones that form around the wearer from programmable matter. Starfleet Academy brings back the life-support belt of the animated series.