Detex, DX-ECL-230D, Battery Operated Exit Control Lock With Alarm, Alarmed Panic Exit Device, Easy to install, rugged, and economical; the ECL-230 series has been the industry standard alarmed exit control lock for more than 30 years. The ECL-230 series has been continuously updated to provide even more options, quality, and value, all in a time tested design. The DX-ECL-230 Exit Control Lock is a business necessity for those businesses wanting the added benefit of exit control with an alarm horn to prevent shoplifting or trespassing. Requires at least one rim cylinder (not included).