The Yale YS170-SL is a lever-operated passive lock for the secondary leaf of a French-door set. This retained version is listed with a 35mm backset, 92mm PZ centres and a 16mm faceplate.
This YS170-SL is the passive-leaf mechanism for a matched French-door assembly. Its handle operates the secondary leaf locking arrangement; the active leaf closes and locks against the correctly prepared passive leaf. Confirm the matching shootbolt connections, master lock, mullion/profile preparation and frame keeps before replacement.
Replacement fit: compare the exact reference and generation, backset, PZ centres, follower arrangement, faceplate shape, case routing, fixing holes, locking-point positions and profile-specific frame keeps. A matching brand or 92mm PZ measurement alone does not establish a direct replacement.
Yale describes tested YS170 doorset configurations and approved hardware combinations. PAS 24 security and BS 6375 performance evidence applies to the relevant complete tested doorset, not automatically to every replacement lock installation. Check the exact doorset specification; BS 6375 is not another security certification.