T3.5V

The only objects with T3.5 classifications in Kirkpatrick20 were
photometric spectral types "[T3.5]" for 
2MASS J21265916+7617440[B] and DENIS-P J225210.73−173013.4B (both were assigned Teff=1190+-79K).

Teff(T3.5V) = 1126 K    ; Filipazzo15 M6V-T9V field calibration 
Teff(T3.5V) = 1191 K    ; Kirkpatrick20 (Table 13 polynomial)
Teff(T3.5V) = 1190+-79K ; Kirkpatrick20 (value assigned to 2MJ2126B and DENISJ2252)

BC_K(T3.5V) = 2.859 mag ; Filipazzo15 M6V-T9V field calibration