Operating Specifications/Standards: Track System: Stereo Playback System: With auto-reverse function switching Functions: Play/Stop/Fast Forward/Rewind/Volume Output Terminal: 3.5mm stereo mini-jack Interface: TYPE-C PC Recording Format: MP3 Body Size: 112 x 80 x 31mm Body Weight: Approximately 172g Power Supply: 2 x 1.5V AA batteries or USB power supply Continuous Playback Time: Approximately 10 hours (using alkaline batteries) ※This product does not have a charging function. ※This product can play normal bias tapes, high bias tapes, and metal tapes, but it does not have an equalizer function to adjust magnetic tape characteristics, wear resistance, or an auto-tape selector function that automatically sets characteristics by recognizing the detection holes of the cassette body. Accessories: USB cable Simple earphones Mini precision screwdriver (optional) Instruction manual (with warranty) ※This product does not come with a dedicated AC adapter, nor are there any such sales options. Regarding Playback Speed: Generally, cassette playback devices (decks, players, etc.) have individual differences in playback speed, and strictly speaking, all speeds differ (by the way, even in the 90s, when cassettes were at their peak, the tolerance of new products sold on the market was said to be 0.5% to 2%). We adjust the playback speed at the factory, but individual differences may occur during initial operation and depending on the frequency of use. This product has a function to finely adjust the motor rotation speed. There is a small hole in the lower right part of the panel on the back of the main unit, and by inserting a minus precision screwdriver (about 1.4mm) into this hole and turning it left and right, you can finely adjust the tape speed. Other: Cassette players may generate electrical "noise" when used near electrical appliances that emit electromagnetic waves. Also, "noise" may be generated by the vibration of the tape. High-spec, high-end models manufactured by major Japanese manufacturers in the 80s, when cassettes were at their peak, had a special stabilizer function to fix the cassette body in an optimal state, reducing vibration and enabling stable sound quality playback with less "noise," but this product is a gadget-like item and does not have high-precision functions. Please understand this beforehand.