it gets complicated yet simple at same time..
standard, HO, VHO & EVHO are wattage not leanth specifiers.
you can tell what lenght the lamp is if you know if you only know the wattage and standard, HO, VHO & EVHO
IE:
t5 14watt is 22"
t5 HO 24watt is 22"
t5 VHO 50watt is 22"
t5 EVHO 95watt is 22" (another year or so before any avail production)
t5 28 watt is 46"
t5HO 54 watt is 46"
t5 VHO 95 watt is 46"
t5 EVHO 180 watt is 46" (another year or so before any avail production)
*my VHO and EVHO wattages may be a few watts off but u get the idea