I usually carry two markers.  A poker chip sized one and a smaller one, just to be courteous when marking near an opponents line.

Some poker chip ones now have a smaller magnetic one inside so you can use both.  Could be used to play mind games in 4BBB matchplay.  Marking with the small marker near your partners line and using the large one near your opponents line!
87-4-4-5-6 (85-4-3-4-4)
JPX850 10.5 Fujikura Orochi 60 S (1 & Draw)
Titleist 915F 15 Diamana Blue S+ 70 S
Titleist 816H2 21 Diamana Blue S+ 70HY S
MP18SC 4-PW PX LZ 5.5
S5 Blue Ion 50/54/58 DG Wedge
Scotty Cameron Newport 2 34"