Plastic Reed switch, Flush (recessed) mount, N/C, 3/8" (9.53mm) diameter x 1 1/4" (31.75mm) length, 3/4" (19.05mm) gap, 12" (304.8mm) leads
https://otwtech.com.au/shop/plastic-reed-switch-flush-recessed-mount-n-c-3-8-9-53mm-diameter-x-1-1-4-31-75mm-length-3-4-19-05mm-gap-12-304-8mm-leads-3831
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