All seat base variants have bellows made of highly flame-retardant rubber or silicone mixes.
These bellows protect the users from injury caused by unintentional intervention in the mechanics, prevent the system becoming soiled and also look good.
The seat bases themselves work based on a proven scissor principle. Thanks to their extremely stable position in maintenance-free PTFE plain bearing bushings and the solid design of all parts, they are torsion-resistant and highly durable even under extreme conditions. Slide rolls made of polyamide also underscore this effect.