What does the Usher of Black Rod wear in parliament?

The Usher of the Black Rod wears a black silk gown, a black silk hat with a gold tassel, white cambric bands (similar to clerical ruffles) and carries the Black Rod, a symbol of authority and office. When the Usher approaches the House of Commons to summon its members to attend to the Royal Assent ceremony for new laws, they knock on the door of the Chamber with the Black Rod, but are refused admission by the Honourable Member for Berwick-upon-Tweed. After an exchange of words, the Usher is eventually allowed to enter and perform their duty.