We always have tons of these around the shop, so our frugal boss says….. Sell some on eBay!!!We love these little MT3608 Step Up Power Booster Modules and use ‘em whenever we can.Don’t let the tiny size throw you… these boards are well crafted, and the electronics offer a lot of features. The MT3608 is a constant frequency, current mode step-up converter intended for small, low power applications. It switches at 1.2MHz and allows the use of tiny, low-cost capacitors and inductors. Internal soft start results in small inrush current and extends battery life. The MT3608 features automatic shifting to pulse frequency modulation mode at light loads. The MT3608 also includes under-voltage lockout, current limiting, and thermal overload protection to prevent damage in the event of an output overload. (Yup, that’s a mico USB port in addition to the input solder pads!!!) Module characteristics: Voltage Boost Input voltage: 2v ~ 24v Maximum output current: 2A Maximum output voltage: > 5v ~ 28v Efficiency: > 93% Product Size (approx.): 31mm * 17mm * 6.5mm (1.22” x 0.67” x .025”) HELPFUL HINTS AND TIPS The input voltage should not exceed 24v Peak output current does not exceed 2A The output voltage can never be lower than the input voltage … it’s the law ….. of physics!!! Output voltage is adjustable With the potentiometer facing towards you, slowly turn the adjusting screw clockwise or counterclockwise – up to ~10 turns are available. While we can’t offer “engineering” help, you’ll find plenty of stuff on the Internet per safe use of the purchased item. Any warranties are limited to replacement of product. SALE IS FOR 6 COMPLETE MODULES Like the slogan of our favorite late-night burger joint says, “Buy ’em by the sack…” SHIPPING We are not quite sure from where or how eBay gets its estimated shipment receipt date, but it seems to be varying from days to weeks for the same item!!! We strive to ship every order within 1 business day (We do NOT ship on weekends). We use (primarily) USPS 1st Class postage service with tracking. USPS does a GREAT job of handling our thousands of packages. They have a few glitches now and then but overall, they provide excellent service. Note that we are not privy to USPS tracking information beyond what you can retrieve via eBay or USPS. If you have ANY questions about your purchase, parcel logistics, etc. please feel free to either send us (using your eBay account) an email detailing the problem OR file a formal request with eBay. We ALWAYS respond to such cases in a positive supportive manner. FEEDBACK Leaving neutral or negative feedback without an attempt to communicate your concern or complaint does nothing to solve your problem. If you are voicing a problem through feedback, we only learn of your dissatisfaction well after the problem has occurred without an opportunity to make the matter right. If you have a problem with the product or an inquiry on the delivery of your order, ASK US!!! Give us a chance to make it right. We are here to make your buying experience a fast, efficient, cost-effective, and pleasant experience. STANDARD DISCLAIMER This Ebay Account Holder is furnishing this item “as is”. We do not provide any warranty of the item whatsoever, whether express, implied, or statutory, including, but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the item will be error-free. In no respect shall we incur any liability for any damages, including, but limited to, direct, indirect, special, or consequential damages arising out of, resulting from, or any way connected to the use of the item, whether or not based upon warranty, contract, tort, or otherwise; whether or not injury was sustained by persons or property or otherwise; and whether or not loss was sustained from, or arose out of, the results of, the item, or any services that may be provided by this Ebay account. If a recognizable item appears in this account, use for commercial purposes may infringe a right of privacy or publicity. It may not be used to state or imply the endorsement by this Ebay account holder of a commercial product, process, or service, or used in any other manner that might mislead. Accordingly, it is requested that if this account is used in advertising and other commercial promotions, layout and copy be submitted to this Ebay Account Holder prior to release. It may not be used to state or imply the endorsement by this Ebay Account Holder of a commercial product, process, or service, or used in any other manner that might mislead. For industrial, hobbyist or experimental use only. We cannot offer advice on a specific application. Buyer should be aware of all necessary federal, state and local safety precautions that may be needed for the proper safe use of the purchased item. Any warranties are limited to replacement of product.