How do Perfect Fit Roller Blinds lock when raising and lowering?

Ensure the bottom bar end caps are positioned in the Perfect Fit frame channel furthest from the window.

Perfect Fit Roller Blinds are operated by tilting the bottom bar back to raise/lower the blind and setting the bar straight to lock.  The end caps compress within the channel to secure the blind at the required level.

Please note if the bottom bar end caps are not sliding within the channel furthest from the glass the blind will not hold.  The image below highlights (red section) the correct channel the bottom bar end caps should slide within.  The bottom bar can then be tilted to raise/lower the blind;