A device configured to be worn by a user is described. The device comprises a first member having an opening and a second member configured to be detachably engaged with the first member. The device further comprises a chamber comprising liquid ink, the liquid ink being in fluid communication with the opening via a passage extending between the chamber and the opening. The device further comprises a locking mechanism configured to switch between a locked state and an unlocked state, and an ejection module configured to eject the liquid ink through the opening of the first member when the locking mechanism is at the locked state thereof.

A painless slow-expanding piercing needle and a method for using same are disclosed. The painless slow-expanding piercing needle includes: a piercing needle with a diameter not greater than 0.3 mm; and a wire having a first end and a second end. The first end has a greater diameter than second end, the second end is connected to the piercing needle, and the first end is curled into a spiral tube shape. After piercing from one side to form a wound, the piercing needle is separated from second end, and the second end is curled into a spiral tube shape and curled up at the other side of the wound. After the wound heals, uncurling the first end by a length, moving the wire toward the second end to a proper position and curling the first and the second ends tightly are performed for several times until hole expansion is achieved.

A needle with an elongated body with a proximal end, a distal end, and a hollow channel, the proximal end configured to penetrate tissue, wherein the elongated body has an upper wall with an inner surface and an outer surface and a bottom wall with an inner surface and an outer surface. The proximal end has a beveled face and an opening within the beveled face in communication with the hollow channel, wherein the beveled face terminates at a piercing tip at its proximal end and has a bevel bottom at its distal end formed by an edge of the outer surface of the top wall. The beveled face has a heel formed by an edge of the inner surface of the top wall delimiting the opening and a bend positioned between the heel and the bevel bottom such that the piercing tip is positioned above the heel.

An earring back for secure but easily releasable engagement with an earring post or extension is provided. In an embodiment, the earring back includes an outer casing and an internal, compressible material such as silicone. The earring back further defines a center opening for receiving and engaging with an earring post or extension. In an embodiment, the outer casing comprises two pieces. A first piece is a back piece with an enclosed back end, an open opposite end providing access to an inner cavity, and a lip extending laterally from the open end. The second piece is a front piece having a radius larger than the radius of the lip of the back piece and defining the center opening. In an embodiment, a circumferential portion of the casing front piece is folded over and around a lip of the compressible material and the casing back piece lip and compressed.

An ear piercing instrument, including: a base housing on which a first mounting cavity extending parallel to a stud piercing direction is provided; and an integrally molded stud piercing housing which is configured to assemble a stud assembly or a stud and fixedly connected in the first mounting cavity by a third snap. The stud piercing housing is provided with a push rod guiding cylinder embedded in the first mounting cavity, and a piercing assembly is at least partially located in the push rod guiding cylinder and is clamped and positioned by both the stud piercing housing and a bottom wall of the first mounting cavity.

A manual ear-piercing gun, comprising a front gun part (1) and a rear gun part (2). The front gun part (1) and the rear gun part (2) are nested and can move linearly relative to each other. The front gun part (1) is constructed to have a mounting groove, and a sliding rail member (6) is provided in the mounting groove. A mounting slot (9b) for an earring backing mounting part (9) is formed between a side groove wall of the mounting groove and the end of the sliding rail member (6) away from the rear gun part (2). A sliding seat (5) for mounting an earring stud mounting part (10) is slidably connected to the sliding rail member (6), and the sliding seat (5) can move along with the relative linear motion of the front gun part (1) and the rear gun part (2).