A matchbox transport vehicle. I have another one in NASA colours which originally had some sort of rocket on the back. I don't know what this rescue vehicle had on the back, possibly a small 'plane?
This is one of the few Matchbox toys that I've seen which actually has a scale noted underneath. This one is 1:150 scale, but I think it looks OK with the 15mm figures (in this case GZG light vacc-suits).