As a fundraising/publicity activity they are auctioning off part of a bugging device which they found in their office some time ago. It was on eBay, but eBay removed it, so now they're selling it on their own website along with a letter of authenication by their President Gerry Adams:
On September 13th, 2004, at a very sensitive time in the peace process, a sophisticated bugging device was found hidden in Sinn Féin offices in Connolly House, Belfast. This was the second device found in Belfast within ten days. Martin McGuinness and I returned the Connolly House device to the British Prime Minister Tony Blair during the peace talks in Leeds Castle, England.
When we were leaving that meeting I held on to a section of that device. Since then I have been in correspondence with various elements of the British system to establish who authorised this electronic surveillance operation. In January 2005 Eliza Manningham-Butler, head of MI5, admitted that MI5 bugged Connolly House.
This note is authentication by me that the section of the bugging device which it accompanies is part of the Connolly House device which was returned to Mr. Blair.