These tunnels are made from the highest quality bamboo by Organic LLC. Wall thickness and hole size will vary, but every pair is an excellent match. The walls tend to get pretty thick for most sizes above 1-1/8″. They have a wearable area of 1/2″ from end to end. The natural cuticle layer is left intact on the wearable area. They tend to select the roundest shape possible, but there is a natural slight irregularity in the shape. We do not recommend these for freshly stretched lobes.