Lidlok remote Locking units are now patented. They are incorporated into the New Flat Top D40 autoremote locking lids and have a wireless over-ride in addition to the noraml Key fob remote. The RX Flat Top Lids can be optionally fitted with these Units. The D22 lids can also utilise these remotes but Flat Top say its not really aimed at this Trady Market. 3 year warranty