The height of this kit and diameter of collar and cuffs is all customizable.If the existing size doesn't fit you,just contact me for customize quotation.Most customize size no extra charge,some special size charge a little extra. Material: stainless steel Kit weight is about 15kg Collar Height:4cm Cuffs Height:6cm Thickness of collar and cuffs:2cm 2 existing size kit optional. female size kit collar diameter 11.5cm, handcuffs diameter 5.3cm, ankle cuffs diameter 7.3cm male size kit collar diameter 13.5cm, handcuffs diameter 6cm, ankle cuffs diameter 7.8cm Because of the heavier weight of this shackle kit, it is recommended to choose a looser size, which will be more comfortable to wear. It is recommended that the diameter of the collar be 1cm larger than the actual diameter of the neck. The diameter of the handcuffs is 0.6 cm larger than the actual maximum diameter of the hands and feet. (The cross-section of the hands and feet is oval, with two diameters. Buy round shackles based on the largest vertical diameter.) So don‘t be limited by the existing size, you can customize more sizes if necessary. The above suggestions are for reference only. Each customer purchases this set for different purposes, and the desired effect may also be different, so please decide on the size by yourself. If you want a lighter shackle set, I strongly recommend the following two styles. https://www.bonanza.com/listings/Integrated-Lock-Stainless-Steel-Collar-Handcuffs-Ankle-Cuffs-Set/1664127803 https://www.bonanza.com/listings/Stainless-Steel-Heavy-Gear-Set-Collar-Handcuffs-Ankle-Cuffs/1664127482 please note that due to all steel restraints gear is handmade,it is unavoidable that a little size error exsits.Around 0.2cm size error on diameter should be accepted. And since this steel restraints kit is so heavy,it may cause a little bit scratch during shipping,if this happen,I need you understand this is out of control,cuffs is not jewelry,I don't accept scratch reason for exchange or return.If you order this kit,means we have the agreement on this.