Element appears to be in the opposite orientation to that in progenitor wX13, but otherwise unmodified, with four copies of the z binding region. The terminal repeats have been modified at both ends and the element is unable to transpose. On the 3' end the 31bp terminal inverted repeats contain a direct duplication of 26bp. At the 5' end the first 17bp of P sequence have been duplicated in a reverse orientation, giving a palindromic structure, and base pair 18 is deleted.
Eye pigment distribution: posterior red crescent.
Sensitive to P-element repression.