Convert Mason jars into drinking cups with these bamboo lids! Both standard and wide mouth sizes featuring a hole wide enough for a boba straw. Made of sustainable, naturally microbial bamboo with a removable silicone seal, The wide mouth is 3" inner & 3 3⁄8" outer diameter; standard is 2 3/8" inner & 2 3/4" outer diameter. Both feature a 0.56" hole.