Replacement Toothbrush Heads Compatible with Philips Sonicare:10 Pack Professional Electric Brush Heads for 4100 6100 &More Snap-on Handles

Customers find the toothbrush heads work well with Sonicare toothbrushes and consider them good value for money. The quality receives positive feedback, with one customer noting they perform as well as expensive ones. The fit and bristle firmness receive mixed reviews - while some say they fit perfectly, others report they don't stay on, and while some appreciate the firm bristles, others find them too hard.