The N505AS-STHSLP1K600 from Nascom is a N505AS short high security loop with 1K resistor and 50 foot leads. Nascom's N505AS HSLP is a high security loop designed designed to protect outside assets including but not limited to trailers, boats, motorcycles, ATV, jet skis, generators, and air conditioners. The N505AS HSLP uses high security contact so introducing another magnet in proximity to the security loop will cause an alarm condition.