Copy data from 1 table to another table using check box datagridview , not happening

i have 2 tables let A & B 

i have to copy data from TblA to TblB using a sql sp in C#.

data's view in datagrid view & check box attached for selecting rows.

But when i am executing query all data of tblA copying to tblB 

but i want only selected row need to copy not all.

SP
---
ALTER procedure [dbo].[sptblStockTransfer]

AS
Begin

insert into tblAssetMaster(SerialNumber,AssetType,HDDSize,RAMSize,MonitorType,AssetMake,AssetModel,InvoiceNumber,AssetStatus,WorkingStatus,InvoiceDate,Remarks)
select SerialNumber,AssetType,HDDSize,RAMSize,MonitorType,AssetMake,AssetModel,InvoiceNumber,AssetStatus,WorkingStatus,InvoiceDate,Remarks from tblStockinWard ;

End

 VS Code
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 private void button1_Click(object sender, EventArgs e)
        {
            int inserted = 0;
            for (int i = 0; i <= dataGridView1.RowCount - 1; i++)
            {
                if (Convert.ToBoolean(dataGridView1.Rows[i].Cells["chk"].Value) == true)
                {
                    con.Open();
                    SqlCommand cmd = new SqlCommand("sptblStockTransfer", con);
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
                inserted++;
            }
            if (inserted > 0)
            {
                MessageBox.Show(string.Format("{0} records inserted.", inserted), "Message");
            }
        }