A planed board 600 x 75 mm hinged to the both sides of the base  board of size 900 x 75 mm. The upper board is fitted with aluminum  railing for smooth flow of steel balls. Both upper boards can be set at  any angle by clamping the wing nuts separately.  Provided with set of steel balls.

Trolley " for use in Friction Board P-748A

made of wood with hook on one side  without wheels. Size 3" x 3”.