Cotton Reel Bobbins 10 Empty Plastic 25mm 1 Inch Diameter Radio Coil Formers

This is ten items of empty plastic cotton reels. The higher pack quantity options are cheaper per item.

I have an unfortunate tendency to use them as radio coil formers for MW and SW bands. The central hole is 8mm diameter, just big enough to slide an 8mm diameter ferrite rod inside for tuning. In this way you can also wind separate coils on two bobbins and "Mr. Slidey" them up and down to adjust the coupling between them, on a long ferrite rod or wooden dowel.

They can also be used for storing cotton, or for the various craft projects that demand empty cotton reels. They are only available in the colours shown, those being 2 red, 2 blue, 2 white, 2 green and 2 yellow.

The diameter of the winding section is 25.5mm and the flanges are 31mm diameter. The length of the winding section is 23mm and the total length is 31mm. No coil winding extras are included, just the reels.