求助英语句子“Please feel free to contact me have any further questions or concerns.”

求助英语句子“Please feel free to contact me have any further questions or concerns.”
这个句子“should you……”是不是等价于“if you should ……”.如果是的话,请给出语法上的理由,
完整的句子是“Please feel free to contact me should you have any further questions or
concerns.”