Return items will be accepted within 40 days when is the date of receiving the goods. Customized items cannot be returned or exchanged. Items bought with an e-gift card are exchangeable only; refunds are not applicable.
Free Gift
Welcome to Roymall, your professional website for purchasing premium department store gifts. We highly value and appreciate your support, and we want to express our gratitude by adding an extra touch of excitement to your purchases. When you shop with us, you not only get to enjoy high-quality products that enhance your lifestyle, but you'll also receive an exclusive free gift with every order you place. Ready to explore our collection and find your perfect gifts? Browse our selection of premium department store items, place your order, and look forward to the excitement of your free gift arriving alongside your purchase.
Shipping Policy
We will work hard to deliver items to you after receiving your orders and make sure they arrive safely. Delivery details will be provided in your confirmation email.In most cases, orders are processed within 2 days.Under special circumstances, it will be delayed as follows: When you place an order on Saturday, Sunday or public holidays, it will be delayed for 2 days..Normally, it needs 5-7 working days (Monday to Friday) without being affected by flight delay or other environmental factors..Because our shipping service is worldwide so the delivery times will depend on your location so it may need a few times and please wait patiently if you are in remote districts or countries.
1. Return & Exchange Policy
We only accept items purchased from roymall.com. If you purchase from our local distributors or other retailers, you cannot return them on our side.Final sales items or free gifts are not acceptable for a return.To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.After receiving return instructions from us, please package up your returned items and drop your package at the local post office or another courier. We will process your return or exchange item within 3-5 working days after we receive it. The refund will be processed and credited automatically to your original method of payment.No returns or exchanges can be accepted if the product was custom produced, including custom size, custom
color, or custom printed.Need more help, please contact us. service@roymall.com or Whatsapp: +447549870296
2.Refund Policy
You'll get a full refund or 100% store credit after we receive the returned package and check it. The refund will be processed and credited automatically to your original method of payment.Please note that shipping costs and any duties or fees are not refundable. The extra shipping costs are non-refundable once the package has been shipped. You are responsible for paying these fees and we’re unable to waive or refund them, even if the order is returned back to us.Once we received and confirmed your returned item, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund.If you have any problems regarding the refund process, please contact us. service@roymall.com or Whatsapp: +447549870296
What"s Stirling Engine?A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work.The engine is like a steam engine in that all of the engine"s heat flows in & out through the engine wall.
This is traditionally known as an external combustion engine in contrast to an internal combustion engine where the heat input is by combustion of a fuel within the body of the working fluid. Unlike the steam engine"s use of water in both its liquid and gaseous phases as the working fluid, the Stirling engine encloses a fixed quantity of permanently gaseous fluid such as air or helium. As in all heat engines, the gen eral cycle consists of compressing cool gas, heating the gas, expanding the hot gas, and finally cooling the gas before repeating the cycle.
How To Use?1. Inject fuel into each alcohol wick with a needle type plus alcohol.2 Full filled the fuel tank.3.Light the alcohol wick and heat it for 30-50 seconds. Clockwise dial the gyro flywheel to start the model operation.(The alcohol wick can not touch the glass hot cylinder )4.Medical alcohol with 95% fuel concentration works best.5.Debugging instructions:If the operation is not good, you can adjust the length of the following two wick, increase the firepower. (The height of both wick can be adjusted) Note: Recommmended age: 14+.Adults" guidance is required for young children.Please add alcohol fuel slowly.Be careful of the fire and keep away from the flammable objects when using the engine. Package Included:1 X Engine Kit2 X Tools1 X Alcohol Bottle ( Alcohol Not Included)
Roymall C.o.
Free Gift
Shipping Policy
Return Policy
Coupon Code
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Learning & Education
Science & Discovery Toys
