Please donot worry .because the air presure will make Whistle.
1.Please adjust lower volume .
2.Choose the suitable ear plug
3.Make sure if you put the earplug tightly,sound leak will make the Whistle.

Payment :
1)We accept Alipay,West Union,TT bank transfer.All major credit cards are accepted through secure payment processor Alipay

ESCROW.
2)We ship to Aliexpress's address ONLY.Please make sure your address in Aliexpress is matched with your shipping address

before you pay.

Shipping:
1)In order to deliver your package fast and accurate,please kindly left us your phone number when you pay,appreciated!
2)Import duties,taxes and charges are not included in the item price or shipping chargs.These charges are the buyer's

responsibility.

Warranty:
1)Item warranty:We provides a limited quality warranty of 12 months for the items sold dating.
2)If your items are defective(not due to misuse or wrong operation).please contact us within 7days be describing the

defects in detail(if convenient and necessary,please send us photos or video clips for the faults of the defective

items).We will have our engineers to analyze the faults and then tell what actions need to be taken for resolving the

problem,if the faults could be solved at buyer's side by a calibration or part change,we will send calibration instruction

or parts to the buyers.if not,the buyers need to post back their defective items to us via their local post office airmail

at their own cost,we will repair or replace the items and then post the repaired or replaced items to buyers via post

airmail at our cost.

Feedback:
1)We guarantee 100% customer satistaction.We will give prompt response to you message and Email(Normally with 24hours from

Monday to Friday China time).If you do not receive our reply,please kindly resend your message or email.we will reply to

you as soon as possible.
2)If you are satisfied with the purchase and our whole service ,your comment is very important in our business

success.Please take a minute to leave us a positive feedback with an overall Detailed Selling Rating of 5.
3)If you are not satisfied with your purchase or our service in any way.please give us the opportunity to resolve any

problem,We understand the concerns and frustrations you might have,and will try our bes to resolve the issues.