Something not often seen, never mind offered for sale…
The pad I believe is the legendary Keystone design as introduced in the 50’s and was manufactured right through to the 70’s. The box features the Blue & Olive 70’s badge so I suspect these are from the 70’s.
Nice condition and great to also have an original box included too.
Sized 13cm x 12.5cm. 1cm in height at one end, 3cm high at the other.