It may look like an instrument of torture, devised by – to quote P.G. Wodehouse in another context – “the nastier-minded members of the Borgia family for people they had a particular grudge against”! But in fact it’s a conformateur, designed to capture the exact shape of your head. Lock’s then use that outline to make you a hat with a precise fit. It’s needed because heads, like humans, come in all shapes and sizes. The conformateur has dozens of pins which rest gently around your head in just the right place for your hatband. The shape is then transferred, scaled down, to the top of the device, which uses a mirror image arrangement of pins to mimic your head shape. You end up with a small card on which your bonce is revealed to all for the comic blob it is.