The Pitlock 4 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 & head set. • 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 Will only work with modern 1 1/8” Ahead stems & not with 1” ahead or quill stems. • Comes with individually coded screw/pit/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