Stemfix™ Caps Low-profile Stem Caps Stemfix (aka "Pin Caps") are low-profile plastic caps, which achieve a secure grip when used in special drilled "head-hole" screws, such as 'SupaChip' or Confirmat screws. Stemfix have a positive grip that is easy to fit, but not-so easy to remove. This makes Stemfix caps an ideal way to hide screws & fixings in: areas accessed by young children (wardrobes & kitchen cupboards) areas acessed by the public (shopfitting, signage, hoardings etc) areas subjected to intense or sustained vibration (caravans, mobile homes etc)