Internal deletion of P{(-FRT)lacZ.HP}, such that the remaining element is 690bp long, with 656bp from the 5' end of the starting element and 15bp from the 3' end, separated by 19bp of AT-rich sequence with no obvious homology to the starting element. The P-element promoter is retained at the 5' end as is the first 65bp of the Ecol\lacZ sequence.