It's probably the best top cap you will ever have.

One piece, bolt & topcap with Allen (hex) 5mm socket. Will fit to every standard starnut. Not suitable for "expanding" star nuts with the steel coil spring (used in carbon steerer). However, it is compatible with ENVE Compression Plug (recommended for carbon steerers).

Specifications
Material: CNC Machined 7075 Aluminium
Key: 5mm Allen
Designed in UK, made in Poland

Mfr Claimed Weight
5g