Only 300 mAh true capacity
These are incorrectly labelled and after being fully charged, will only deliver 300 mAh before going flat (I bought four and they are between 292 and 301 mAh in true capacity).
If you set aside the fact that the capacity is misleading, they are otherwise fairly decent. The built in protection circuitry means you don't have to worry about them being over-discharged and damaged when using them to replace AAA batteries (when you replace each pair of AAAs with one of these and a "placeholder battery" of course, to keep the voltage similar).
The protection circuit means they are 1mm longer than a AAA, so make sure any device you intend to use them with has springs or similar in the battery compartment that will allow a battery very slightly longer than a AAA to fit.
Of course thanks to the misleading label you are paying for capacity that isn't there, so I'd only recommend buying these if you can get them at a similar price to those labelled at 300 mAh.
Verified purchase: YesCondition: New