The flag is made of fine cotton sheeting with a cotton hoist and is hand sewn. It is appliquéd with a figure of an African, holding a staff, in brown fabric. His garments and the ribbons on the staff are fluttering in the breeze, mirroring the wind blowing out the flag. The figure is shown with a protruding tongue. A rope is attached to the hoist. Inscribed on an associated paper label: 'Flag taken from a slaver captured off the east coast of Africa & sent to my father (W H Wylde of the Foreign Office) by Commodore Eardley Wilmot.'

William Henry Wylde (1819-1909) was a superintendent of the Commercial, Consular and Slave Trade departments of the Foreign Office 1869-80 and was a member of the commission which sat in London, 1865, to revise Slave Trade Instructions. Arthur Parry Eardley Wilmot (1815-1886) was employed in anti-slavery operations off West Africa— in Harlequin 1850-53 and as Commodore in Rattlesnake 1862-66. He was promoted to flag rank in 1870. His naval career ended shortly afterwards when his ship Agincourt struck a rock near the bay of Gibraltar. William Wylde's involvement with anti-slavery operations continued into the 1870's when the British moved to suppress the trade in Zanzibar.