The Smarkey Heated Jacket Battery Step-Up Adapter Charger Cable is specifically designed for 7.4V and 8.4V heated jackets, heated hoodies, and heated vests. This adapter cable works seamlessly with QC 3.0 and PD function power banks, boosting your power bank’s output from 5V to 9V.The heated jacket adapter cable only work with QC 3.0 Power Bank or PD function Power Bank. NOT work for old version power bank which USB outlet is 1.0A, 2.0A, 2.1A, 3A. This 9V Heated Jacket Battery Step-Up Adapter Charger Cable compatible with Most 7.4V or 8.4V Heated Jackets! NOT compatible with Craftsman, AEG, Revean, Metabo, Milwaukee, Makita, or Snap-on 12V heated jackets due to differences in connector size and voltage.(Most 12V heated jackets use 5.5mm connectors) Heated Jacket Battery Charger Adapter Cable works with most 7.4V or 8.4V heated jacket available on the market, like Kobalt,Smarkey, oroxx Brand. (Most 7.4V or 8.4V heated jackets use 3.5mm or 4.0mm connectors, which are compatible with this 9V heated jacket step-up cable.) Q001. Why your Jacket cannot work with this Cable? ? A001,This TypeC Heated Jacket Charger Cable is designed to boost the output from your QC 3.0 or PD-enabled power bank from 5V to 9V. It only works with power banks that support QC 3.0 or PD functions. This Adapter Cable will NOT work with older power banks that have 1.0A, 2.0A, 2.1A, or 3A USB outputs. (Most of the time, Your Heated Jacket won't work because your power bank doesn't have Real QC3.0 or PD function ) Stay Warm Anywhere with the Smarkey Heated Jacket Battery Step-Up Adapter Charger Cable Designed for 7.4V and 8.4V heated jacket, this innovative adapter cable allows you to connect your heated jacket directly to any compatible QC 3.0 or PD function power bank to provide the extra power boost needed to keep you warm in harsh conditions. Simply connect the Heated Jacket step-up adapter cable to a QC 3.0 or PD function power bank, and it will step up the voltage from 5V to 9V, providing the perfect amount of power for your heated gear. It's compatible with most 7.4V and 8.4V heated jacket on the market, including heated hoodie and jacket vest. Note: This adapter cable will not work with older power banks that have 1.0A, 2.0A, 2.1A, or 3A USB outlets. Before purchasing, ensure that your power bank supports QC 3.0 or PD functionality for proper voltage conversion. This Heated Jacket Battery Step-Up Adapter Charger Cable is also not compatible with 12V heated jacket from brands such as Craftsman, AEG, Milwaukee, Makita, and Snap-on, as they require different connectors and voltage specifications.