Title:
Watermark detector. H&A Wallace 'The Philatector' electric watermark detector boxed with instructions and filters in a card case. II. Card box, in two parts. Bottom part is plain, with no details. Lid plain, with a sticker attached on the front reading 'The PHILATECTOR ELECTRIC WATEMARK DETECTOR' 'AC' 'FULLY PATENTED' alongside an illustration of the unit being held with a hand and projecting the 'AC' insignia.