I don't recommend the use of these.
A major flaw is that if you are lifting a tile to meet another, a void will be created where there is insufficient adhesive underneath the tile, causing a weakness. This type of device will cause the most vulnerable part of a tile to be prone to damage as it lifts the edges and corners.
They also rely on plastic parts to remain in the adhesive, which don't have the same properties as a continuous adhesive bed. If a tile failure was to occur, both of these facts would allow a tile adhesive manufacturer to dismiss any claim against them.
A major flaw is that if you are lifting a tile to meet another, a void will be created where there is insufficient adhesive underneath the tile, causing a weakness. This type of device will cause the most vulnerable part of a tile to be prone to damage as it lifts the edges and corners.
They also rely on plastic parts to remain in the adhesive, which don't have the same properties as a continuous adhesive bed. If a tile failure was to occur, both of these facts would allow a tile adhesive manufacturer to dismiss any claim against them.