Having already the older test of the SKH 60 C1 in mind i immediately understood that it was exactly the same model with the only difference on the round plastic of the rear of the headphone.
My daughter already used the remain two earphones for short time after they have been damaged in their cables from her furriness to do her next task until the one of the ear was totally broken .fortunately the older model that was bought yeas ago still operates well with its very sharp audio , good for using with a poor sounded audio gear of the ..far past!
They were tested with the 1103 Degen radio using the standard earplug and Silvercrest with the aux output. Second test was in an old analog Bolong radio.
Therefore i can suppose the headphones are nearly identical to the previous model i used
Update 21/3/21 Sad to notice the long use can annoy well my years. After one of the cables from my main Sennheiser earphones was cut after it fallen in the floor and dragged by fault by my feet they wee the only I could use due to their smaller size good fit with an audio that is with less trebles . Other headphones use are quite bassier or treblier and irritate my quite fast my head. Even that they are not so stiff in the head they can hurt the years after around 2 hours of continuous use from the pressure … I think you understand what I mean with that!