Package Included: 1x YSA Double Shot 151 Full Keycaps + Puller This cute keycap set is YSA profile which is ball shape,which is lower than SA.The height difference can be seen from the image The legend is double shot which is never faded.The thickness is around 1.75mm for double layers The keycap is made of 50% PBT and ABS.The surface feeling is smooth but won't easy to oil like full ABS. Compatible with standard ANSI 108 104 87 61 MX switches mechanical keyboard whose space is 6.25u