You just selected:
B-EXT-1R
Code Gecko
0610-100005

B-EXT-1R
Extension board kit for additional relay, for IN.YE-V3 only

You should also consider these companion products:

B-EXT-COM-RS485
Code Gecko
0610-100006

B-EXT-COM-RS485
IN.YE-5-H4.0-AMP-V3FLX-GE1
Code Gecko
0610-221126-698

IN.YE-5-H4.0-AMP-V3FLX-GE1
BDLYE5K450 IN.YE-5 IN.K450 IT3 CABLES
Code Gecko
0610-300013

BDLYE5K450 IN.YE-5 IN.K450 IT3 CABLES
Continue shopping