This is the first standalone charger available for the Sony RX100. (Despite its hefty price, the RX100 did not have a standalone charger included, which meant that you couldn't charge a spare battery while using the camera.) As stated in the product description, it is charger designed for multiple Sony battery types. If you have a bunch of Sony cameras, this is a very nice feature, as it reduces the number of chargers you have to buy or carry.
In practice, however, I've found that the design of this charger leaves a lot to be desired. Since it has to accommodate a bunch of different battery sizes, it doesn't fit any one battery type perfectly. There are a series of grooves, springs, and levers to "guide" each battery type into the correct position for charging. The NP-BX1 battery (the RX100's battery) takes up only half the space available, and unless you align the battery perfectly along the right half of the space, it doesn't charge. At least a couple of times I had to jiggle the battery to get the charge going. The overall charging process is fairly quick, and a series of green LED lights shows how much charge the battery has.
The charger itself is relatively large (3.5 x 2 x 2 in) compared to other compact camera battery chargers. Again, if you have some Sony SLR cameras, this is not a big issue, but if you only have the RX100 and bought it for its portability, having a bulky charger is somewhat disappointing. At least the outlet prongs fold inward for travel.