Standard sizes, small, medium or large available.  Comes with standard 2mm pin jack connector already attached.

Small is 25mm (1 inch) diameter and 65mm insert-able length (2 1/2 inches)

Medium is 32mm (1 1/4 inch) diameter and 70mm insert-able length (2 3/4 inches)

Large is 39 mm (1 1/2 inch) diameter and 87 mm insert-able length  (3.4 inches)