The 'holdout' device made c.1940s by Jon Martin, $4400 (£3260) at Potter & Potter.

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The ‘holdout’ was worn on the arm under a coat. When activated, it shot out from the sleeve to deliver or steal small objects, then retracted out of sight.

Estimated at $1500-2500 and sold for $4400 (£3260) on December 15, it was one of the many objects offered in the regular Magic Sale held by Chicago saleroom Potter & Potter (20% buyer’s premium).