The TM48 is an accessory for the TM500 battery monitor, this unit was discontinued a while back Schneider no longer provides this part. However we do support it, many other distributors do carry this part and can be purchase through them. Furthermore. here is the manual for the TM500 as well as the images of the TM48
Connecting the Shunt Board:
Remove the fuse from the in-line fuse holder by rotating the fuse holder cap counterclockwise.
Connect the ring terminal from the fuse holder to the battery’s positive terminal.
Connect the shunt communications cable into the RJ11 jack on the shunt board. This cable can be extended up to 100 feet (30 meters).
Replace the fuse in the fuse holder. Replace the fuse holder cap by pushing and rotating it clockwise.