Red Hound Auto Trailer Coupler Receiver Tow Hitch Lock Brass Pin Latch with 2 Keys 1 brass coupler lock with 2 keys 1/4" x 3/4" (1/4" diameter, spans 3/4") Constructed of heavy duty brass to reliably protect your trailer, boat or RV Durable, ready to handle tough environments 1 year guarantee against workmanship and defects