Your search for hifiman returned the following:

Planar magnetic headphones

IN STOCK

5 people say 

• planar magnetic drivers for low distortion and warm, detailed sound
• open-back design for spacious soundstage
• use with a portable player or pair with a headphone amp for improved performance

Stereo headphones

IN STOCK

• warm, detailed sound mimics HiFiMAN's higher-end planar driver headphones
• open-back design for spacious soundstage
• easily driven by a portable music player

In-ear headphones

IN STOCK

• configure for balanced or unbalanced miniplug connection
• 2 channel-reversing adapters (balanced and unbalanced) for wearing earbuds backwards and wrapping cables behind ears
• 5 pairs of ear tips for comfortable fit and noise isolation

In-ear headphones

OUT OF STOCK

• warm, full-range sound
• 4 pairs of ear tips for comfortable fit and noise isolation
• frequency response: 15-22,000

Headphone amplifier

OUT OF STOCK

• high-power, Class A MOSFET headphone amplifier
• built-in high-performance preamp with 3 inputs and one output
• locking standard full-size and four-pin XLR headphone output jacks

Vacuum tube headphone amplifier

LOW STOCK

1 person says 

• hybrid tube/solid state design for powerful, detailed sound
• dual-chassis design with separate headphone amp and power supply blocks
• high-output capability ideal for high-performance headphones

Vacuum tube headphone amplifier/USB digital-to-analog converter

OUT OF STOCK

4 people say 

• vacuum tube input stage for smooth, detailed sound
• built-in USB DAC for connecting to a computer
• stereo RCA analog input

Planar magnetic headphones

OUT OF STOCK

• planar magnetic drivers for low distortion and warm, detailed sound
• frequency response: 8-65,000 Hz
• balanced single crystal copper XLR cable (6 feet) and unbalanced adapter (3 feet)

Planar magnetic headphones

IN STOCK

5 people say 

• planar magnetic drivers for low distortion and warm, detailed sound
• open-back design for spacious soundstage
• frequency response: 15-50,000 Hz

8GB portable digital music player

OUT OF STOCK

• plays MP3, AAC, WMA, as well as high-resolution WAV, FLAC, Ogg Vorbis files
• built-in dual 16-bit DAC (digital-to-analog converter)
• built-in headphone amp

USB digital-to-analog converter/headphone amplifier

IN STOCK

2 people say 

• USB powered, no batteries or external power supplies needed
• minijack headphone and line-level audio outputs
• easy setup — no additional software required