Mono miniphone plug (3.5mm - 1 ⁄ 8") to mono phone jack (female 1 ⁄ 4" - 6.3mm).  The adapter is approximately 10 inches long.

One common use would be to connect inexpensive radio slave receivers with 1 ⁄ 4" (6.3mm) phone plug sync output to studio flash units such as the Alien Bees, Elimchrom D-Lites and Calumet Genisis.  The right angle connector reduces the strain on the cord and allows the radio slave unit to hang without undue strain on the flash unit's sync port.

Price: $9.00 + shipping