The Ultra Flex is designed to provide very little or no resistance to the actuator that would cause a toggle switch to trip. It still provides a UL recognized sealing performance that meets the NEMA 4, 4X/IP68 sealing standards. To avoid unintentionally tripping a sensitive toggle switch, into the on/off position, APM recommends attaching the APM HEXSEAL® 1131/60 ( full boot ) or 1132/60 (half boot) inverted bellow toggle switch boot.There are an increasing number of toggle switches that when covered with an environmental sealing switch cover can trip the switch into the “on/off“ position due to the mere physics of being covered by the wrong type cover. APM uses low durometer rubber in many cases to guard against this tendency. However, there are an increasing number of toggle switches where this strategy alone is not sufficient and our “Ultra Flex Series" with a bellow design incorporated therein is very able to combat this problem.Full sized toggle switches that have an extremely light actuation force should use the 1131/60 model. Miniature toggle switches that have an extremely light actuation force should use the 1132/60. These models, along with hundreds of other APM HEXSEAL® products, are used extensively by the US Military. Other industries these boots are used in are marine, industrial, construction and commercial.