YVS 410 TU/TUH Window System YVS 410 TU/TUH MULLION OPTIONS 13/16 " [20.6mm] 3-7/8 " [98.4mm] SECTION 39 VERTICAL STACKING MULLION (BLOCK & TACKLE BALANCES) SECTION 39A VERTICAL STACKING MULLION (ULTRA-LIFT BALANCES) Page-14 05-1010-07 | Effective Date: April 1, 2018