A simple kit to understand the difference between ‘mass’ 
and ‘weight’. It consists of 2 metal trays 130 x 55 x 25mm 
(l x b x h) held 200mm apart by 2 spring steel strips. One 
tray is clamped to a table by means of a ‘G’ clamp and the 
other having 3 holes to take 3 equal mass cylinders each of 
200g is free to oscillate. Supplied with 3 equal masses 
and ‘G’ clamp. Overall dimensions: 310 x 130 x 25mm (l x b 
x h).