Compatible with All SNAP-ON Philips Sonicare Electric Toothbrush handles NOT Compatible with Essence, 5611/01 E-Series, HY1200 NOT Compatible with Philips One Series Compatible with Philips Sonicare brush head system: snap-on Compatible with DiamondClean brush handles(ALLModels)9322 9331 9332 9334 9336 9340 9342 9350, 9351 9352 9361 9362 9371 9372 9381 9382 Compatible with ExpertClean(ALLModels) Compatible with ProtectiveClean(ALLModels) Compatible with 4100 new 4100 4100+(ALLModels) Compatible with FlexCare (+)/ FlexCare Platinum(ALLModels)6921 6930 6950 6972 6973 6992 9140 9141 9142 6970 6934 6902 6903 6910 6920 6932 6985 9110 9111 6911 6952 Compatible with HealthyWhite (+)(ALLModels)8923 8911 8918 6710 6712 6722 6730 6732 6733 6750 6761 6781 6782 6780 Compatible with EasyClean(ALLModels)6201 6211 6212 6220 6231 6221 6250 6252 6253 6530 6510 6511 6512 6552 Compatible with Sonicare for Kids(ALLModels)6311 6320 6322 6330 6340 Compatible with 2 Series plaque control(ALLModels)6220 6211 6231 6201 6212 6221 6250 6252 6253 Compatible with 3 Series Gum Health(ALLModels)6631/01 6632/09 6616/50 6616/51 6616/52 6631/01 Compatible with Essence+(ALLModels)3211 3281 3211 3281