I designed these tools after struggling to open split rings and keyrings with a damaged thumb. I have trialled them in PLA and PETG and on a range of keyring sizes and found it perfect for my needs. I kept them small and light to fit in my maker drawer but also with loops in case someone wants to hang them. 

I designed the vertical wedge to just pry the ring open, slip in a metal key and remove the wedge, letting the key guide itself through. 

I designed the horizontal wedge after making an anxiety relief keyring with 5 printed parts, and wanted the tool to guide them through, keeping the weight of the metal ring off the plastic printed parts.