For more than 100 years Thun has been producing and distributing components for bicycles. The family business particularly focuses on transmission parts such as bb-sets and sensor technology for e-bikes. With highly efficient processing, Thun produces more than 50,000 units per day. Thun is distributed worldwide and has become one of the world's market leaders due to its superior technology.These bottom brackets are designed for children's bikes. This bottom bracket features a hollow axle specifically designed to be lighter than most of their other bottom brackets.A carbon composite is implemented into these, meaning no grease is needed to attach to your frame, and will work exactly how you want it to. Perfect for frames with damaged threads, these bottom brackets attach with ease.Thun recommends NOT greasing the bottom bracket as this could swell the plastic and cause issues.**Ideal for children's bikes as used by Frog bikes****Technical Attributes*** Material: Cold forged, Zinc and BB-O coated steel spindle* Carbon composite: Sleeves and cups* Sealed bearings* Right cup compatible with PEDRO's key* Hollow axle: For a lighter bottom bracket* Square tapered* Weight: 198g