This is a Tinkercad remix from mjf55's (6 pin clip 0.1inch) which is in turn derived from (5 pin clip 0.1inch for Sonoff Basic) - thanks for your help, Mike :) Notes: Sonoff's RE5V1C 5V wifi relay uses 7 pogo lands at 1.75mm spacing itead of 2.54mm (0.1inch) header connecto of the older devices and I've run into a few other devices at this spacing The target board only has 7 pcb lands. The clip has 8 pi to allow for encounte with as-yet unknown futire devices works with 16mm pogo pi - nailpoints recommended as this is contacting pcb lands, not through-holes Spring is a "9mm x 35mm compression" from 200 piece assortment off Amazon (similar kits are apparently available from Harbour Freight for about $4 but that doesn't exist around this part of Europe)