Up to 4. Every item page has the same field in its sidebar.

Stat	Copper Blade D1ChineseGeneral × Change General General · DEF Seal of Star SoX Seal of Moon Seal of Sun Plus0123456789101112
Melee Attack Power	16~18
Magical Attack Power	24~26
Melee Specialization(%)	32.4~36.9
Magical Specialization(%)	49~54.8
Accuracy	24
Critical	1
Durability	69

Orange is the higher stat, ranked by the middle of the pair ((min + max) / 2): 23~28 against 20~34 has no answer without a rule. The faint number is how far that column sits behind. Values are what the item has empty. A dash means the item has no such stat at all — not that it has zero.

Nothing here is ranked: a lower required level is an advantage to one player and a different item to another.