BRAND NEW! This is a high quality Taiwan MADE T ring for Pentax K bayonet 35mm cameras. This allows you to directly fit your camera onto many telescope accessories to take pictures and also other lenses and microscopes use the 42mm T thread. The name is the T-4 adapter ring. It is for non autofocus Pentax cameras using the bayonet lens system. Get it here at a great price too! Thanks!