Thanks Tim, this is what they are
and they are the solution to the plastic plants in wooden vivs keep falling down, they are supplied with two stainless steel screws for attaching to vivs simply place the plastic stem in the hole and no more fallen plants

For acrylic plastic and glass vivs they can be stuck on with aquarium silacone.
These can be made to order if interested @75 pence each.via paypal I expect to get some moaners who can make them themselfs for less and they are not patented so go ahead Dimensions 42mm long x 20 mm wide x 8mm thick . PM me or ask here if any interest.