Military origin capacitors that were used for military equipment of the former Soviet Union and that were rediscovered as one of the best capacitors for audio thanks to their good finish, very precise specifications and properties when used on guitars, basses, amplifiers of recognized brands, Danny Gatton, HI-FI equipment etc... This capacitor is ideal for use on your 50s and 60s Fender guitar to give a darker sound

They are made of an aluminum foil plus dielectric that is made with Oil Paper. Their tolerance is 10% and they withstand quite high temperatures.