With continuous usages the seals wear out. When the GRABO seal finally wears out, the lifting capacity diminishes. In this case you can replace the worn seal by hand within seconds.
You can use the spare one supplied with the kit. Alternatively you can buy as many from any of the distributors or retailers. This patented high friction foam-rubber seal fits all GRABO models.

Black foam seal

• Material: SBR rubber foam sponge
• Color: Black
• L x W x H: 11.5 x 6.9 x 0.7in (293 x 175 x 19 mm)
• Density: 10.6 Lb/cft (170 kg/m^3)
• Hardness, Shore C: ~10 +/-2
• Tearing Pressure: 1800 Psi (126 kg/cm^2)
• Compression to 25% size at: 8.5 Psi (6000 kg/m^2)
• Water Absorption, %: <=5
• Shrinkage at 160F (70C) for 24 hrs., %: <=20
• Recommended Storage Temperature: Room temperature

Red seal

• Material: Silicon Foam
• Color: Red
• Density: 40.5 Lb/cft (650 kg/m^3)
• Hardness, Shore C: 55 +/-5
• Water Absorption, %: <=4
• Recommended Storage Temperature: Room temperature