Which one is better?

http://accessories.us.dell.com/sna/ProductDetail.aspx?sku=A0516729&c=us&cat=snp&category_id=211&cs=19&l=en&Page=productlisting.aspx&fe=mnf&mnf=2314&k=

or

http://www.amazon.com/exec/obidos/tg/detail/-/B0007SM8R8/ref=ord_cart_shr/002-7206728-2539215?%5Fencoding=UTF8&m=ATVPDKIKX0DER&v=glance