press stud 
noun British
A small fastener on clothing, engaged by pressing its two halves together.The bag is a sort of rounded flattened truncated triangle shape, pleated onto the top band which closes in the centre with a magnetic press stud....
- Perhaps a press stud could also be inserted at the same time as the silicone, to enable their tops to remain attached!
- The black purse, with a silver zip and press stud, is still missing.