First, the height of the batteries is approximately 1 mm larger compared to a conventional LR6. It does not look like much, but in practice it is necessary to systematically force to insert the batteries in electrical appliances, which overwrites their connectors. To remove them, you have to help a small screwdriver for example (batteries being trapped).
Then, oddly these batteries only work on about 1 unit of 5 (even banal small flashlight will not turn on) even after charging on a branded charger Varta (which works very well for many years); besides the batteries are normally already loaded at purchase. All of my devices are operational with other batteries. I bought 4 packs and tried all batteries have the same defect.
I already bought this brand of batteries (another model) and I was nevertheless satisfied. I will turn now to the Varta / Energizer / Duracell lower capacity (1800-2000 mAh).