I has used two additional screws M3-16mm to fix rollers and two M3-16mm screws to fix the slider base on the printer (see attached files). Material: Nylon but it can be a PLA! Two small rollers helps to reduce the friction inside the end-switch body during filament movements back and forward. This update reduce undesirable vibrations created buy friction and give the possibility to use the same end-switch for both filament's rollers positions.