A clinometer is one of those things you may not know you ever needed until, of course, you realise what it does: it determines the height of things, or their angles or levels. Not something that one would find in every school cupboard, but a resourceful teacher could find plenty of potential uses. Usually these gadgets are none too user-friendly. But Invicta, a plastics company in Leicester, has devloped a nice, chunky version, with component parts which are easy to read even by primary children, and which looks ideal for collecting environmental data either out in the wilds (measuring trees or hedges) or in a built environment (buildings, bridges). And it costs less than pound;10.

Details: Sue Dockrell, Invicta Plastics, Harborough Road, Oadby, Leicester LE2 4LB. Tel: 0116 272 0555