It is a class room demonstration kit for qualitative investigation of nature of mass and making students understand distinction between mass and weight.

Kit comprises two metal trays 130 x 50 mm held 200 mm apart approximately on spring steel strips attached to the sides. One tray has holes to take three equal mass cylinders approximately (L x D) 100 x 25 mm each. The other tray acts as anchor and may be clamped to the bench either horizontally or vertically. Three support pins are supplied to fit radial holes in cylinders. Supplied complete with G clamp for mounting.