Coto High Reliability reed switch has SPST contacts that have Ruthenium on gold plating. The normally open contacts close when a permanent magnet is brought near (momentary action). When the magnet is removed the contact opens. Rated 250mA. These were made for use in their relays to be operated by coils wrapped around them. Size of glass envelope 0.62" L x 0.086" W. Sold in a package of 10.