I marked up three separate positions on multiple walls for inserting tacks, I successfully inserted all three with the plunger of the gun fully pressed, the tacks were flush to the wall so everything told me it had worked and was safe to attach one of the supplied picture hangers and hang my framed art (weighing less than 8kg). I successfully hung one of my framed pieces and that was enough to convince me to proceed with the remaining two locations. It wasn't until I attempted to hang the second piece that I realised the tacks were not secure, the moment I put any weight on the second tack it pulled from the wall along with a chunk of the plasterboard, if I wasn't already holding the framed art it would have smashed on the floor, this frame is well below the 8kg weight limit so the tack should have supported it. In fact I realised the third tack could easily be pulled out of the wall using my finger tips! I tested the Takker on the same wall repeatedly to make sure I hadn't just been in an unlucky spot and every time the tacks would not securely stay in the wall even though the plunger was fully pressed down and the tacks sat flush to the wall surface. I decided to check the first piece I successfully hung was sitting on a secure tack and sure enough that tack was easily pulled out the wall with minimal effort using just my fingertips, so I was very lucky that frame had even stayed on the wall. The only explanation I received for this failure was that sometimes plasterboard walls are different and do not hold the tacks properly, so buyer beware of this because that note isn't mentioned anywhere on the site or product specs. Test all your tacks cannot be easily pulled out BEFORE you hang anything on them.