It is possible to divide roughly into soft and firm Ball stretcher, depending on the material used.
As a rule, the soft ball stretchers have a higher wearing comfort than those made of steel. They can be applied without tools, can be worn over a long period of time (and without applying) even under street clothing and for example in the job or in sports, nestle against the body. It may even be a proper fit that the wearer "forgets" after a short familiarization that he is wearing a Ball stretcher. Materials for soft stretchers are usually leather, silicone, latex, silicone and plastic blends as well as neoprene.
Soft stretchers, depending on the material, are subject to wear and limited durability due to aging processes. They are becoming increasingly porous and the ductility and retraction ability of the material, to the original diameter, leaves little in the course of time. At some point the silicone and plastic materials tear. However, if you have the right care, you can enjoy it for years.
The only exception is leather.
This will be harder at worst and the wear comfort will change slightly. However, leather has a clear disadvantage against the other ball-stretch materials: you can not usually wash and disinfect it. But also here, by good care you have here also longer joy of the Ball stretcher.
In the case of the fixed Ball stretcher, one or two pieces are made of different metals. In particular, the cheap Ball stretcher is mostly inferior steel, which is provided with a surface coating which, at first glance, is very similar to that of stainless steel.
It has already been mentioned that the cheap stretchers mostly come from foreign production and hardly a seller knows which material and manufacturing standards were used. For this reason, it is not unusual for allergic reactions or peeling of the surface coatings. These are significant signs of inferior materials or inadequate processing. But somewhere the price difference has to come to high-quality materials and processing yes ...