Material: stainless steel, exquisite manual polishing, fine workmanship 1 Set includes collar, handcuffs and ankle cuffs PLease note that although the size option marked as female size or male size,but it doesn’t mean the size would fit all female or male,this is impossible.So before purchasing,self measurement is necessary. If the exsiting size doesn’t fit you,customize size option is available. Custom size range have some limitation, if your custom dimensions can't be made or need to charge some extra(will contact you),please understand. Collar shape is always circle by default. But for custom size option, you can custom its shape as well. For handcuffs and ankle cuffs,there are 2 styles to offer, circle cuffs and oval cuffs. Size information: Circle Style: Female Size Kit: collar inner diameter 11.5cm, handcuffs inner diameter 5.3cm, ankle cuffs inner diameter 7.3cm, height 3cm,thickness 1.1cm. Male Size Kit: collar diameter diameter 13.5cm, handcuffs inner diameter 6.0cm, ankle cuffs inner diameter 8.0cm, height 3cm, thickness 1.1cm. Oval Style: Female Size Kit: collar inner diameter 11.5cm, handcuffs inner diameter 4.8*5.8cm, ankle cuffs inner diameter 6.8*7.8cm, height 3cm,thickness 1.1cm. Male Size Kit: collar diameter 13.5cm, handcuffs inner diameter 5.5*6.5cm, ankle cuffs inner diameter 7.5*8.5cm, height 3cm,thickness 1.1cm. 1cm=0.4inch please note that due to all steel gear is handmade,it is unavoidable that a little size error exsits.Around 0.2cm size range error on diameter should be accepted.