These are a kind of spacers that contrary to other spacers have no clips
to hold re-bars , and are made of various stands with 25mm height. Each
pair of the stands are attached to each other. They are 25cm in length
used to create concrete cover under precast rebar network with a
dimension of 100X100mm or 150X150mm. Pad fix chair spacers are also used
in slabs and construction of floors for halls and
enclosures.