The Gretsch USA Custom Microsensitive butt plate is a modern update to the classic Gretsch Microsensitive from the 1950s and 60s. Improvements have been made to internal mechanisms for solid, dependable functionality. Made from heavy-duty zinc alloy and will fit the original hole patterns, which allows drummers to retrofit their original butt. The Microsensitive system is dual tensioning. Macro step adjustments are made with the small knob on butt plate. The butt plate attaches to shell with single post. Uses key screws for the strainer plate.