Define variable with the proper data type. Improper data type may cause conversions which is not good for performance.
DECLARE @Name VARCHAR(50)
SET @Name = 'Blade'
SELECT ProductID
,Color
,Class
FROM AdventureWorks2016.Production.Product
WHERE name = @Name
Execution plan
As you can see, SQL server is doing an implicit conversion to compare @name variable with the name column because the data type of name column is nvarchar while @name variable is declared with data type varchar so implicit conversion is happening to convert varchar value to nvarchar.