_HISTOIRE D'EAU_ HISTORY OF SWIMWEAR. WOOL TWO-TONE BELTED JANTZEN "MEN'S TOPPER" SWIMWEAR 1932. FOR THE FIRST TIME IN THE HISTORY THE MEN'S SWIMWEARS BECOME DIFFERENT FROM THE WOMEN'S SWIMSUIT. WITH THE TOP PART DETACHABLE FROM THE TRUNKS.

The battle to liberate the male chest for public exposure was long, arduous,and far from decisive. The "Topper", one of the earliest "emancipated" styles, dating from 1932, offered its wearers the option to go bare by providing a detachable top. A zipper held it to the trunks-or, more accurately, to an athletic supporter worn beneath the trunks. If a swimmer wanted, he could detach the top. Many men did, and often were arrested for indecent exposure
(source from: "MAKING WAVES" Lena Lencek-Gideon Bosker)