As of 2015, Leslie Locke brand attic fans are manufactured and sold under the Master Flow brand name. Master Flow roof mount vents for attics can be purchased at the Home Depot, which offers several models.
The GAF Company purchased Leslie Locke Building Products in 1998, and created a new manufacturing division. LL Building Products makes attic ventilation vents that once carried the Leslie Locke branding. Master Flow vents are specifically designed to blow hot attic air up through the vent and outdoors, resulting in a cooler attic space. Special features on Master Flow vents include pre-punched flashing and an adjustable thermostat. The vents include a heavy-duty screen material that effectively keeps away bugs, birds and animals.
In addition to cooling the attic, ventilation fans help homeowners save money on energy costs by lowering the amount of energy used by a cooling system. Running an attic fan during hot months also preserves the longevity of the roof. Ventilation removes excess moisture and heat that can damage the roof structure over time. Attic fans are also beneficial for a home during the winter months. Proper attic ventilation helps prevent the formation of ice dams, which can damage a roof due to leaks from trapped water. The attic fan maintains an even room temperature, which prevents uneven hot and cold spots on the roof.