For the ultimate close-to-the-scalp haircut, the following types of hair clippers and techniques can achieve a cut closest to a razor, requiring a combination of tool characteristics and operating skills:

1. Professional Bald/Extremely Short Clippers

Wahl Balding Clipper: Designed for extremely short hair, equipped with a #2105 surgical-grade blade. The fine, sharp teeth allow for close scalp movement, achieving a near-bald effect. Keep the blade parallel to the scalp during use and avoid applying excessive pressure.
Andis BGRC Balder: The curved blade design conforms to the skull's curvature. The powerful motor prevents jamming when handling coarse hair, making it suitable for large-area close-to-the-scalp trimming.

2. T-Blade Clipper (Precision )Contour Trimming

Andis T-Outliner: Features a narrow, straight carbon steel T-blade, ideal for sculpting sharp hairlines and sideburns. The blades need to be periodically "zero-gap adjusted" (manually calibrated until the upper and lower blades are fully aligned), otherwise small stubble may be left. During use, glide the blade along the hairline in one direction only to avoid repeated shaving.
Wahl Detailer Li: A cordless, portable model with a T-shaped head design, suitable for localized trimming such as trimming stray hairs at the nape of the neck. The high blade density, combined with skin stretching, can achieve a cutting length of 0.2mm.

3. Zero-Gap Modification Technology

Manual calibration improves skin contact: Most hair clippers have a safety gap between the blades at the factory. After removing the head, gently tap to adjust the position of the upper blade until it is completely aligned with the lower blade (zero gap), which can significantly improve the cutting tightness. Warning: Improper operation may cause skin abrasions; beginners should attempt with caution.
Pre-adjusted zero-gap models: Some versions of the Wahl Legend are factory-preset with zero gap, eliminating the risk of modification, but the blades heat up faster, so the duration of each use should be controlled.

4. Unprotected Comb Techniques

Suitable Scenarios: Only recommended for areas with smooth hairlines, sideburns, etc., or for experienced individuals styling full-head baldness.
Key Techniques: Tensile the skin with one hand – while holding the clipper in the other, gently sweep against the direction of hair growth (e.g., from bottom to top at the back of the neck).
Use a "light-touching" motion, avoiding lingering in the same spot.
After finishing, apply an alcohol swab to soothe the skin.
Risk Warning: Direct contact with the skin can easily cause scratches and folliculitis. Not recommended for bony prominences (cheekbones, back of the head).