I believe you have a copy (fake) of this coin:

Heritage World Coin Auctions > CICF Signature Sale 3032    Auction date: 10 April 2014
Lot number: 24856

Price realized: 1,500 USD   (Approx. 1,081 EUR / 894 GBP / 1,316 CHF)

Great Britain
WIlliam I the Conqueror (1066-87) Penny c.1068-70, Oxford mint, Wulfwi as moneyer, S-1251, North-842 (S), Bonnet type, MS62 PCGS. PILLEMVS REX A, crowned and diademed bust facing with two fillets to each side / PVLFPI ON OXEN, voided short cross, arms extending from a central annulet with limbs terminating in two crescents and a pellet, pile in angles with pellet at tips. A superior example of this issue, sharply struck with remarkable surfaces. The cabinet patina is truly lovely and in combination with the detail of the devices and underlying luster, this coin deserves the attention of an advanced collector.

Estimate: 3000-3500 USD