B&L photo prism 

• Description: Overstock from my lab. It fits top of B&L projection eyepieces, but it may be used with other too. Insertion Ø is: inner 27,8mm / outter 28,8mm. Clean and nice prism with no issues. Tilt is easily adjusted by tilting head up / down (it has long screw at side that sustains tiliting mechanism)
• Issues: marks over body from usage, but very clean overall