BDA = Bottom Loading Dial Adjustable Depth Control. A key feature that characterizes the ability of a stapler or nailer to be "TUNED" to match precise applications, is a Dial A Depth Control that "stays put." You set it where you want it to be for the perfect degree of countersink. Solidity, ease and speed of Loading are part of the advantages that draw many to the bottom load style tools in this 18, 17, & 16 gauge range of power house staplers. ...But of equal importance is the hidden advantage of the built in "jam clearance" where an open bottom load "channel" let's you flick away any bent staple that might ever clog the works. When 1-1/2" to 1-9/16" leg length applications call for a CLASSIC design of stapler to ensure steady performance, these Omer Bottom Load long lasting industrial caliber tools are the answer.