Darkrp mad cow weapons problem

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I mad my Black market dealer be able to sell knifes and they completely work but I keep getting this saying:
WARNING: The model of shipment Knife is incorrect! can not create custom shipment!

[LUA]AddCustomShipment("Knife", {
model = "models/weapons/w_knife_t.mdl",
entity = "weapon_mad_knife",
price = 3000,
amount = 10,
seperate = false,
pricesep = 350,
noship = false,
allowed = {TEAM_BLACK}
})[/LUA]

Anyone know what the right model?