The Pitlock 3 Piece Skewer Set is a coded high security protection device that is a direct replacement for the quick release skewers on front/rear wheels & seat posts. You will need a 14mm spanner to fit them You must carry the key & spanner with you whilst cycling to allow wheel removal for punctures etc. Can only be used on bikes with QR skewers & will not work with solid nutted axles Set features front / rear wheel & seat post skewers 1 Pits & 1 Security Code ID Duplicate keys can only be ordered using the security code supplied Parts made from quality rustproof high-grade steel Easy to install & use