Exactly, but the picture (product) you posted have opening mouth of up to 5.5 cm (I guess, but @Photon doesn’t) which is not adequate for batteries with width of cca. 6.0 cm, like the one in Librem 5. Therefore if you are still considering to buy some universal battery charger, that is based up to max. charging of 4.2V (as already and properly advised within this Forum), you might end up with this one:
Needed to update this thread while:
Thank you both!