What a wand does
What a red light wand or handheld is for
A wand puts a small cluster of LEDs at zero distance on one spot: a line on the face, a knuckle, a tendon, a scar, the jaw. Because the diodes are inches from the skin, even a 15-LED handheld delivers a full dose to a few square inches in 3 to 10 minutes. The trade-off is coverage: treating a whole face or a knee with a wand means moving it across several spots, which is why masks, pads and panels exist for larger areas.
Wands are the right buy for targeted facial use (the "red light therapy wand for face" search), for travel, for a first device under $150, and, at the top of the range, for practitioners who want laser-class output in a handheld.