tModLoader Error CS0246 D:

[Chisaki]

Hi all, I wanted to be able to use the glow armor in Starbound as some sort of vanity for my playthrough so I:

followed youtube tutorials on how to make Tmodloader armor, etc.
here is the result:

Spoiler: code

using Terraria.ID;
using Terraria.ModLoader;
using Terraria;

namespace SBCosmetics.Items.Armor
{
   public class GlowHelm : ModItem
   {
     public override bool Autoload(ref string name, ref string texture, IList<EquipType> equips)
     {
       equips.Add(EquipType.head);
       return true;
     }
   
     public override void SetDefaults()
     {
       item.name = "Glow Helmet";
       item.width = 18;
       item.height = 18;
       item.toolTip = "A luminescent mask - light up the night!";
       item.toolTip2 = "+5 Defense and you shine with the hole set!";
       item.value = 500;
       item.rare = 2;
       item.defense = 5;
     }
   
     public override bool IsArmor (Item head, Item body, Item legs)
     {
       return body.type == mod.ItemType("GlowSuit") && legs.type == mod.ItemType("GlowPants");
     }
     public override void UpdateArmorSet (Player player)
     {
       player.setBonus = "SHIINNNEEE";
       player.addBuff(BuffID.Shine, 2);
     }
     public override void AddRecipes()
     {
       ModRecipe recipe = new ModRecipe(mod);
       recipe.AddIngredient(ItemID.DirtBlock, 1);
       recipe.AddTile(TileID.WorkBenches);
       recipe.SetResult(this);
       recipe.AddRecipe();
     }
   }
}

results in a

c:\Users\<derp>\Documents\My Games\Terraria\ModLoader\Mod Sources\SBCosmetcs\Items\Armor\GlowHelm.cs(9,70) : error CS0246: The type or namespace name 'IList' could not be found (are you missing a using directive or an assembly reference?)

atm the mod only has the helmet (was trying to test out the helmet to see if it looked okay)