Kinetic theory model kit (three dimensional) by Philip Harris Ltd.

Kinetic theory model kit (three dimensional) by Philip Harris Ltd., Catalogue No. P7975, consisting of perspex tube fitted with paper piston, metal cap at one end, and rubber diaphragm at the other end, plus card weights, spare diaphragms, reel of binding silk, packet of phosphor-bronze balls, and sticker for attaching to vibrator unit, boxed, as new (without vibrator unit)