The ParMarLow ES-RUB earphone from TWITCO is designed similarly to the ES-MUR earphone, but with a soft rubber-like housing. This allows for a more secure and comfortable fit on even the smallest of ears. Like all ParMarLow earphones, the ES-RUB is available in cable lengths of 39 and 18 inches and either a 2.55mm or 3.5mm phone plug. A 3.5mm threaded plug version with 39 inches of cable is also available.