Durex Extra Safe Condoms (3). Durex Extra Safe Condoms are slightly thicker and more lubricated than our standard condoms to help those who want reassurance and don’t want to sacrifice comfort.. Extra lubricated slightly thicker Easy-on shape for greater comfort. Nominal width 56mm. Transparent, extra lubricated and teat ended. 100% electronically tested. Durex Extra Safe is designed for those who want peace of mind in knowing that the condom they are using is slightly thicker. However, just because you want the peace of mind that comes with reassurance doesn't mean you want to sacrifice comfort - and with the Extra Safe, you don't have to.