This kit is simply an upgrade to the current Weber Smokey Mountain latch system.  
The lift and turn latch system is specially designed to pull the door shut against the body. In conjunction with a gasket seal, you create a very tight seal meaning no more smoke leakage and better temperature control via the top and bottom vents. 

For ultimate look and heat retention, we advise you purchase the full upgraded Cajun Bandit door, but this system is a good first step if you're looking to improve your WSM performance.