Diamond set cap, simple and elegant style. Easy to make and would suit beginners to pen turning. Accessories: Slimbushing (RZ-BP3#-BU) 7mm Drill Bit (RZ-DB007) 7mm Tubes (RZ-BT3) Pen mills(RZ-PM011). Tube Size:6.8*6.29*51.7mm. Tube Price is based on one pack(5 PCS).