Which solar twilight sensor is needed for this troll?

The matching sensor 3711 is available in different lengths:

Length 0,75m - Art.No. 7000 00 88

Length 1,50m - Art.No. 7000 00 89

Length 3,00m - Art.No. 7000 00 90

Length 5,00m - Art.No. 7000 00 91

Length10,00m - Art.No. 7000 00 92