Replacement prisms last updated  June 2020 so OUT OF DATE
I will do a stock check asap (August 2021)
I have over 150 different sizes of prisms in stock.
I have not carried out a stock check for some time 
but I believe I have at least one of each of the following sizes.
Please note that even 0.5mm can make all the difference between 
a prism fitting or not. All measurements are in mm.
Prisms cost from £2 to £12 each but as Zeiss Jena prisms are so difficult to obtain, I do not sell them.

Column One is my stock number. I know it's strange but it has evolved over 30 plus years.
Column 2 is the length of the base.
Col 3 is the height.
Col 4 is the width.
Col 5 is the shape of the base. Standard; wedged or rectangular.
Col 6. In some sizes you have the choice of Straight sides; one sloped side or two.
Col 7 gives any special features, such as a cut base.