English to French Tech/Engineering Engineering (general)

The method of simultaneously producing a pair of composite shingle units (...) which comprises:
- programming a cutting machine to cut the central portion of a shingle membrane in a pattern for producing an opposing and matching pair of rectangular tabbed top sheets having their respective tabbed portions in abutment, each top sheet being marked with a horizontal nailing line located immediately above each of the opposing tabs

C'est surtout "tabbed" qui me pose problème.
Que diriez-vous ?

Merci !