The smallest and best(!?) rangefinder camera ever built.
The XA started out as a rangefinder, and very good it was too, through the years the design got modified and the XA1, XA2, XA3 and XA4 all followed.
The later models were 'zone focus cameras and the superb OLYMPUS XA site gives further details.
I only have an XA,XA1 XA2 and an XA3, the XA4 proving to elusive or expensive to consider.
In use the XA is simple to use giving good results with a usable depth of field, the rangefinder being simple and easy to use.
The XA2 lacks the range finder, instead it has a 'zone focus' lens. Again it's easy to use and gives good results.
As with the others, the XA1 is easy to use. The lens is slower at only f4, and there are no batteries used. The shutter release is by a prominant, clumsy looking button.
If you want a 35mm pocket camera these deserve very serious consideration with their ease of use and excellent lenses. If you only get one get the XA, you'll not be disappointed.