With or without Overflow (See Accessories to add Overflow Hole to Sink)
An overflow is a small hole along the inside wall of a sink that prevents water from spilling out of the sink if the drain is closed or clogged. Water drains through the overflow channel inside the sink until it meets the drain at the bottom of the sink. A drain with overflow holes is needed when a sink has an overflow, in order for the excess water to drain properly. If the sink does not have an overflow, then a drain without overflow holes would be required to prevent any leaks.
Description:
Able to fit a 3-1/2" drain opening, the Lever Drain by John Boos has a twist or straight action handle design. The drain is available with or without an overflow hole, and has a 2" outlet.