CRL 4" x 10" Center Lock Glass Keepers with 12V DC ST125 Series Deadlatch Electric Strikes are handed to match the appropriate Center Lock. To simplify ordering use the same handing as the lock. That way you match the Glass Keeper with Deadlatch Electric Strike to Center Lock handing, which eliminates confusion. These units are special order and can be shipped within one week. For more information, contact CRL Technical Sales Department. Glass Cut-Out Required.