I got mine from a club mate who worked in a creamery. Originally they contained frozen concentrated orange juice. This was about 25 years ago, and I'm still using them. Very durable, heavy plastic with lift off lid. Not sure of size, but each bin holds 2 x 25kg of mixture. Same bin still available locally (2nd hand) cost approx. £6-£8. Have one in each loft so I can feed different mixtures within each loft, and have a few more in workshop to store conditioning seed etc. Was actually thinking of getting a few more to store our wild bird seeds in.