Three primary locks needed for trailer security. #377DAT 1-7/8" & 2" coupler lock for unattended trailers, #1475DAT 9/32" x 7/8" coupler latch lock, to lock coupler on to ball while attached to the vehicle & #1473DAT 5/8" & 1/2" x 2-1/2" universal receiver lock to secure draw bar in the receiver. Keyed alike convenience. Storage case included