The 1186 is the recommended horn speaker accessory for the Algo 8180 and 1825PM products. Note: As an alternative to the 8180+1186 combination, the 8186 SIP Horn Speaker is available as an all-in-one SIP and PoE endpoint. The 8186 will provide the same performance as the 8180+1186 and is outdoor rated. No power supply required – draws power from the 1825 or 8180 devices