Wearing of clothing made from Latex.
The sexual arousal due to the wearing of latex clothing, accessories.
Modern era theorists believe that one's attraction to Latex, or associated fetishes, is due to the ability to be someone different. That the material itself helps accent one's sexual prowess, while maintaining some secretive nuances of the person under the material.
Some believe wearing Latex / Rubber is a form of sexual bondage as well. That the material is more akin to having a second skin, restraining the original skin, and organs.
It is also a highly 'visible' source of arousal. This is due to its tightness, its shine, and at times, it's colors.
As well as being a 'visual' turn on, the scent or smell of latex / rubber can be very arousing for some. Smell is a very powerful sense.
Primarily, the wearing of such material is to create a different identity. To be someone else, or have the appearance of being someone different.
Basically, to be a fan of latex, one dresses in latex or rubber materials. This can be jackets, pants, underwear, or anything really. While 'latex fetishists' prefer the pure 'latex', substitutes of 'rubber gear' and other similar material can be used.
The 'concept' is that wearing of latex is like having a second skin. It heightens the sexual appearance of the wearer. It is supposed to arouse. In some 'views' it is also a sign of power, of having power.
For example, in Batman Films, he is dressed in Rubber. Creating an illusion of power, of secrecy as well. The idea being that behind that suit is someone totally different, part of the appeal for many into the Latex / Rubber fetish.
Use of rubber toys is one more reason. It is sanitary, and further seems to illicit a sense of sexuality that ordinary clothing or apparel doesn't.
There are several related fetishes, that some say are interchangeable. PVC or Rubber being two of them. In the more purist sense, Latex / Rubber fetishists attempt to include 'normal attire' into their desire to wear latex. This will include using things like gas masks, or adapting hazmat suits.
The sexual acts are also generally more extreme in nature. Vanilla type sex is not generally associated with those in these fetishes. Generally some form of SandM or BDSM is incorporated into the sex play of Latex Fetishists. This also involves, perhaps, a greater use of sexual toys, or implements, due to their 'rubber' manufacture.
Surgical Gloves for example, or catheters are some of the 'toys' used, and originally due to their being made of Latex / Rubber.
Material for plastics, clothing.