BTB Controller Arm for Orange Blades:
Long end for: WK24ZRS, WK24ZVRS, WK24RS
Short end for: WK4ZRS, WK4ZVRS, WK4RS
While cutting against the pinchweld (not against the glass), use the WK11CW control arm underneath all Orange and Blue reverse blades, to provide support to reciprocating blade and avoiding flapping