In 2014 paramount discovered a problem with the Ultra UV. The heat from the lamps was causing the threaded ring at the top of the system to crack. The only way to fix the crack was to replace the housing.
As a solution paramount used an aluminum lamp holder in the top section that would allow the lamps to sit farther down in the quartz sleeve. In doing so they needed to shorten the lamps so they would fit in the court sleeve. This kept the heat from the lamps away from the loom threaded portion at the top of the housing, thus eliminating the cracking that was occurring due to the heat. The new design is called Ultra UV2
In order to support Customers that own the Ultra UV they developed the kit that would allow these customers to upgrade to the Ultra UV2 (sku 005-422-9015-00). Customers who currently own the Ultra UV2 do not necessarily need to purchase the kit when replacing lamps. In many cases the container and lamp retainer do not need to be changed, and only the lamps need replacing. On occasion the lamp retainer at the bottom needs to be replaced as it has fused to the old lamps.
If you are unsure of which lamps you require the link below should help in making that determination: Lamp Selector
