On Order Exfo Survey Battery Li-ion Battery fits Exfo, Ex1 3.7V, 3400mAh CS-EFX272SL $36.36 The battery that is shown here is manufactured using the best designed components and the highest quality parts. Battery selection is confusing. Leave the selection stress to the experts if you are really not sure. We can be contacted easily by live chat or by email. We almost always will respond to your query within a business day. Add to cart