MW0GKX.co.uk
Battery Information
Battery Details

Don't confuse with the 333 Silver Oxide cell, which is only 1.55 volts but the same size.

Renata (the only maker) has ceased production of this battery (see the information letter).

The Renata 333 is obsolete and rare to find.
As mentioned above, the 333 Silver Oxide cell, which is only 1.55 volts but the same size would be an option but this is becoming difficult to get hold of too!.
The next closest size wise is the 339 (6.8 mm × 1.4 mm) .4 mm thicker and the lower voltage of 1.55 volt.

Equivalents:

333, Renata 333, RT-333, XR611W,

Image not to scale.	Common Name.	Dimensions. Diameter × Thickness.	Chemical Composition.	Nominal Voltage.
	333.	6.8 mm × 1 mm Contacts: Case and flat side Positive. Raised area Negative	Lithium (single use).	2 volts.