Gilbert Catalog
Price in 1949: Unlisted
Spectacular new way to make train automatically open and close switches, blow whistle or operate No. 592 Crossing Gate, No. 761 Semaphore and other equipment. Easily attached to any track section. Weight of passing train does the rest. $1.75. Denver and west, $1.85.

Price in 1951: Unlisted
Makes your switches automatically non-derailingl

Price in 1954: $1.50
Automatic track trip switches automatically non-derailing