The 1 1/4" Wilkins 950XLT Double Check Valve Assembly was introduced in 1997 and is still currently in production. The 950XLT is a two cover, top load design design with test cocks on top of the device. It was created as an alternative to the 950XL which is a wye pattern and has side test cocks. The checks are a poppet style and are not self contained. There is spring pressure against the covers. A seat removal tool is required for seat service.