Which firmware is the latest?

We have lots of Tentacles here.. some have the firmware 3.71 installed, some 3.70. Downloaded the latest Tentacle setup software and could not upgrade the 3.70 to 3.71. Is there any difference in the firmware? How can i update the 3.70 equipped Tentacles to 3.71? Even on your website, the Tentacle setup software is described with 3.70 inside.

Thanks and best regards,

Clemens