Thanks.
These are single sided, Russ. First intention was making them double sided, but it interfered with the requirement of making them smallest possible and I decided to make them this way. The plunger stroke is 5mm, dimensions are 29x23x14mm. You supply anything between 5 to 15VDC and output is active low. Price is $30.
Hood, yes, they are based on the same concept. The new ones are an entirely different design (round frame with M12x1 external thread - like the industrial proximity switches) and they are single ended as well.
Dan