Patent pending design, the BT7 series of locks are primarily used on boat trailers with surge brakes.  The BT7E Trailer Coupler Lock is designed to work with forged and stamped surge brake couplers made by Dexter.  This lock works with 2" ball size.  Limited Lifetime Warranty.
 
All locks can be keyed alike.  If you buy multiple locks and want them keyed alike please add a note to your order.  I will contact you for details.