The Nikai Trimmer NK-2289 is a popular model of rechargeable, cordless hair and beard trimmer.1 It is designed for both personal grooming and professional use.2Here are the key features and specifications based on product listings:Key Features & SpecificationsFeatureDetailOperationCordless and Rechargeable (USB Charging)RuntimeLong-lasting battery, typically 150 to 200 minutes of continuous cordless use.Charging TimeFast charging, usually a full charge in approximately 3 hours.BladePrecision blade, often with an adjustable length mechanism.Adjustable Blade LengthThe main blade length can typically be adjusted from 0.8 mm to 2.0 mm (zero-gap possible on some models).Guide CombsComes with 4 adjustable guide combs for varying hair lengths.Comb SizesCommon comb sizes are: 3 mm, 6 mm, 9 mm, and 12 mm.MotorLow noise motor.DesignErgonomic and lightweight for comfortable handling.IndicatorLED indicator light for charging status.UsageSuitable for haircuts, beard trimming, and styling.