plastic screw wall plug
Nowadays, one of the most common designs for light loads is the split-ribbed plastic anchor. It consist of two halves that noticeably increase their separation (split) as the screw penetrates between them. As its name suggests, this type of anchor also has ribs on the outside to prevent the anchor from slipping out of the hole as the screw is driven in. This type of anchor is also known as a conical screw anchor.