4x4mm with 1mm hole. Replace them with these soft plastic ones sold in sets of 25, 50, 100.
25 50 100 Soft Plastic Earring Backs 4mm Stopper Stud Ear Nuts 0.5mm Hole UK
Soft Plastic Earring Backs 4mm Stopper Stud Ear Nuts 0.5mm Hole 200 Per Pack UK
100x earring backs, Soft rubber earring backs, 4mm, clear, plastic earring backs
50/100 925 Stamped Silver Plated Butterfly Earring Backs Scroll Stopper Stud 291
100-500X Silicone Soft Rubber Earring Backs Replacement Stopper Earnut Pads UK.
100-500X Silicone Soft Rubber Earring Backs Replacement Stopper Earnut Pads UK
