The most common problem is the cable which is commonly poorly wrapped and leads to breakage. Some headphones have replaceable leads, this is a good idea, as is replaceable ear cover for when they perish or become dirty. Quality brand such as Sennheiser and Beyer are reliable over the long term. Electrostatic is a method of driving the speaker diaphragm. An ultra thin membrane is made to move by applying a current to it.
Most electrostatic headphones require an 'energiser' a box of tricks to make the headphone work.
The sound quality from quality electrostatics such as Stax or Sennheiser is quite superb, but so is the price which can reach into many thousands of pounds. Hi-Fi Corner stocks and recommends Sennheiser, and some Beyer models. Stax are available to special order only. Wireless sets from Sennheiser normally in stock. To save you searching for this often asked question we've got the information from Sennheiser below.