1. 5 holes,PE bag each set 2. Stainless steel, plastic, rubber 3. SAE,BSP 4.Good surface treatment, Feature:material: SUS316description: SUS 316 C-ring with 5 holesspecification: 54mmfunctions:1.to fix the sensor out of the fuel tank by those 5 holes2.if there is no screw holes to fix the sensor, the 5-hole C ring can be another choice.5 holes,PE bag each setStainless steel, plastic, rubberSAE, ...