RF 321 - Tapered Stand Up Spring for;
- Series 30 Blocks RF30100 & RF30110
- Series 50 Blocks RF50100, RF50110, RF50200, RF50210, RF50300 & RF50310
- Series 60 Blocks RF866, RF867, RF868, RF869 & RF870
May Suit Other Blocks, the spring is 28mm base diameter, 20mm top diameter, 40mm long.