This trident corresponds to the original which we know from a piece of relief dated 3rd century AD, found in Rome, Vigna Aquari.
Length (wooden shaft plus trident): 132 cm / 51.9"
Length of the metal pikes: 23 cm / 9"
Width of trident: 32 cm / 12.5"
Weight: 1.9 kg / 4.1 lbs