Neiko 50443A Universal O-Ring Assortment | 407-Piece Set | SAE Provides sealing and prevents leaking for a wide range of applications such as plumbing, machinery, hydraulic & pneumatic repairs and much more Commercial grade Nitrile Butadiene Rubber (NBR) formulation featured with excellent oil and UV resistance Super pliable construction and extra thick wall design stands for long term service and durability Includes 32 common standard sizes from 1/8 I.D. x 1/4 O.D. to 2 I.D. x 2-1/4 O.D. Comes with a heavy duty storage case that keeps each size separated and organized