You will receive the coin shown in the four pictures.

Details:

Composition:     0.9167 Fine Gold
Weight:               39.94 grams
Diameter:            38.61 mm


The following, detailed information is from NUMISTA.COM:

Commemorative issue   

The end of the second millennium AD

Obverse

Fourth crowned portrait of HM Queen Elizabeth II right, wearing the Girls of Great Britain and Ireland tiara, legend around.

Lettering:
ELIZABETH·II·D·G REG·F·D·1999
IRB

Unabridged legend: Elizabeth II Dei Gratia Regina Fidei Defensatrix

Translation: Elizabeth the Second by the Grace of God Queen Defender of the Faith

Engraver: Ian Rank-Broadley 

Reverse

A representation of the British Isles with a pair of clock hands, pivoted on Greenwich and set at twelve o'clock, commemorative dates either side, denomination below.

Lettering:
1999 2000
ANNO DOMINI
JM
FIVE POUNDS

Engraver: Jeffrey Matthews

Edge

Plain with incuse lettering

Lettering: WHAT'S PAST IS PROLOGUE

Mint

Royal Mint, Llantrisant, United Kingdom (1968-date)