Define a custom SQL type in a Fluent NHibernate mapping file

Using a Custom Fluent NHibernate Type.cs

public class FooMap : ClassMap<Foo>
{
	public FooMap()
	{
		Table("Foo");
		
		Id(f => f.Id, "Id").GeneratedBy.Identity();
		Map(f => f.CustomField).CustomSqlType("varchar (60)");
	}
}