They are swimwear material but can also be worn as underwear.
Mens Unlined Swimwear for sale
Las mejores ofertas en Sin marca para Hombres Swim calzoncillos trajes de baño
JAXFSTK UNLINED MEN'S swimwear/posing/underwear briefs £12.06 - PicClick UK
Las mejores ofertas en Unbranded talla L tamaño regular Hombres Swim Briefs
JAXFSTK UNLINED MEN'S swimwear/posing/underwear briefs £12.06 - PicClick UK
ADIDAS INFINITEX MEN'S swim brief, blue + blue/red trims, 32, 34, 38 & 42 $23.00 - PicClick
Mens Unlined Swimwear for sale
LAHUA MEN'S 'BLUE zebra' swim brief, sizes M, L, XL & XXL (from 28-36/38) £24.67 - PicClick UK
Mens Unlined Swimwear for sale
Best fred perry men's swimwear prices we found
SPEEDO ENDURANCE 5CM Logo brief, Black/White, sizes 34, 36, 38 & 40 $26.24 - PicClick
Best fred perry men's swimwear prices we found
ZOGGS AQUALAST MEN'S swimwear briefs, Navy Blue, sizes 20 (38), 22 (40) & 24 £18.41 - PicClick UK