Exclusive pack of gears for the classroom. Perfect for Design & Technology.Contents:10 x each of 10 20 30 40 and 50 tooth 2mm gears2mm bevel gears and interlocking racks10 x each of 10 20 30 40 and 50 tooth 4mm gears4mm bevel gears and interlocking racks5 x 2mm steel axles5 x 4mm steel axles